(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "The Structural engineer; the journal of the Institution of Structural Engineers"


Univ. of 
Toronto 
Library 



THE CONCRETE 
INSTITUTE 

AN INSTITUTION FOR STRUCTURAL ENGINEERS, 
ARCHITECTS, ETC. 

TRANSACTIONS AND NOTES 




INDEX 

TO 

VOLUME IV. 

[COPYRIGHT] 




Published at the Offices of 

THE CONCRETE INSTITUTE 

Denison House, 296, Vauxhall Bridge Road, Westminster. 



TA 

v.4- 



INDEX TO VOL. IV. 

PACE 

Accessions to the Library xi, xxiii, xxxiii, liii 

Acids, Oils, and Fats, upon Concrete, Action of 503 

Action of Acid-;, Oils, and Fats upon Concrete 532 

Addresses, Presidential ... 1, 406 

/Esthetic Treatment of Concrete ... ... 111 

Annual Dinner, The Second ... ... ... ... 288 

Annual General Meeting, Third, May 9, 1912 ... ... ... ... 262 

Beams with Various Degrees of Fixity, The True Bending Moments 

of 182 

Bending Moments of Beams with Various Degrees of Fixity, The 

True 182 

Bills of Quantities for Reinforced Concrete 435 

Buttress Masonry Dam, Calculations in the Design of a Thrust ... 299 

Calculations in the Design of a Thrust Buttress Masonry Dam ... 299 

Concrete, Action of Acids, Oils, and Fats upon 503 

Concrete. I >i 1 1 -> of Quantities for Reinforced ... ... 435 

Concrete in its Legal Aspect ... ... 532 

Concrete in Southern Nigeria, Reinforced 397 

Concrete, Iron Preserved in ... ... \v 

Concrete, The Consistency of, Interim Report of the Reinforced 

Concrete Practice Standing Committee on 76 

Concrete, Some Recent Works in Reinforced ... ... 17 

Concrete Structures on Completion, Report of the Tests Standing 

Committee on the Testing of Reinforced ... 210 

Concrete, The .Esthetic Treatment of ... ... ... ... ... m 

Concrete Work, The Standardization of Drawings of ... 75 

Consistency of Concrete, Interim Report of the Reinforced Concrete 

Practice Standing Committee ... ... •.:. 76 

Corresp< mdence — 

Alford, J. S 578 

Burton, W. E 450 

Tanner, Sir Henry 448 

Scott, A. Alban A. 570 

Council, Report of the, for 191 1-12 202 



iv INDEX 

PAGE 

Dam, Calculations in the Design of a Thrust Buttress Masonry ... 299 

Dams, High, of Great Length 14(1 

Deceased Members ... ... ... ... ... ... ... ix, xxiii 

Degrees of Fixity, The True Bending Moments of Beams with 

Various ... ... ... ... ... ... 132 

Design of a Thrust Buttress Masonry Dam, Calculations in the ... 299 

Dinner, The Second Annual 2SS 

Discussion at Meetings : Participation therein by — 

Adams, Henry, M.Inst.C.E., M.C.I 203, 209, 254. 255. 260 

Alford, J. S., M.Inst.C.E., M.C.I ' ... 572 

Ball, Valentine 565, 567 

Bare, T. E 463 

Behar, Maurice, M.C.I. 170, 288 

Bolton, Arthur T.. F.R.I.B.A 127,137 

Boulnois, H. Percy, M.Inst.C.E., V. P.C.I 276, 424 

Bungard, Arthur W., L.R.I. B.A., M.C.I 251 

Butler, D. B., Assoc.M.Inst.C.E., F.C.S., M.C.I. 93, 244, 515, 518, 525 

Bylander, S., M.C.I 88,103,170,462 

Cross, A. G., F.S.I 450, 462 

Cubitt, Horace, A.R.I. B. A 570, 571, 573, 574 

Davis, W. E., Q.S.A " ..." ..." 468 

Dudley, R., Assoc.M.Inst.C.E. 172, 173 

Etchells, E. Fiander, F.Phys.Soc, A.M.I.Mech.E., 66, 99, 106, 137, 

166, [68, 22:,, 237, 387, 551, 557. 561, 5(12. 563, 564, 565, 560. 571, 57s 

Fraser, Percival M., A.R.I.B.A., M.C.I. , 63,95, 2 47> 49 2 i 5 X 9> 5 2 °i 5-7 

528. ~,2q, 570 
Gadd, \V. Lawrence, F.I.C., M.C.I., 514, 520, 523, 524, 525, 526, 527, 

528, 529, 530 

Hill, Osborn C. F.R.I.B.A ^2,56:, 

Hingston, Frederic M., Q.S.A., M.C.I 487,521 

Holman, G. E 207 

Hood, W. R., F.S.I 472 

Humphrey, Richard L., M.Inst.C.E., M.Am.Soc.C.E 392 

Kahn, Moritz, M.C.I 490 

K'earns, R. M., F.S.I 466 

Kirkaldy, William G., A. M.Inst.C.E., M.C.I. ... 242, 2=,2, 2X5, 390 

LascclW. W. H., M.C.I 569 

Marsh, Charles F., M.Inst.C.E 65,161 

Meik, C. S., M.Inst.C.E., V.C.P.1 427 

Perkins, W. G., M.C.I., 172, 465, 521. 527, 528, 555, 564, 570. 572, 574 

Pite, Beroiord. F.R.I.B.A., M.C.I. 141.282 

Potter, Thomas, M.C.I 98 

Remnant, A. C, F.S.I. 500 

Riley, W. E., M.Inst.C.E., F.R.I.B.A 290 

Roberts, George S.. M.C.I 253 

Robertson, D. Webster, M.C.I 216 

Rogers, Major H. S., R.E., M.C.I. 562 



INDEX v 

PAGE 

Discussion at Meetings : Participation therein by — 

Ross, Alexander, M.Inst.C.E., P. V.P.C.1 14 

Ryves, Reginald, M.Cons.E., A.M.I.C.E., M.C.l 174. 179 

- lis, Edwin O., F.R.S.Ed., V.P.C.l [2,274,383 

Scott, A. Alban H., MS. A., M.C.I, [25,171,255,257,259,285,451, 

45"- 5i s . 55 2 i 575 

Serraillier, Luci en, M.C.l 87,140,275 

Shepherd, Herbert, A. R.I.B. A., M.C.1 138, 139. 5°3 

Sinclair, R. N., M.C.l 246 

Solly, J. B. Travers, A. M.Inst. C.E., M.C.I 250 

Somerville, D. G., M.C.l 66 

Steinberg, Herbert E., A.M.Insf.C.E., M.C.I 217 

Tanner, Sir Henry, C.B., I. SO., F.R.I.B.A., F.S.I.. F.P.C.I., I, 2, 16, 
17, 68, 134, 140, 273. 27s, 280, 281, 284. 286, 392 

Theobald, John M., F.S.I, M.C. 1 435,496.41)8 

Trechmann, A. O., F.C.S., M.C.I 245, 254 

Vawdrey, K. W., Assoc.M.Inst.C.E., M.C.I. 75, 83, 103, 206, 209, 4S4, 

514, 519, 322. 525, 526 

Walker, E. G., Assoc.M.Inst.C.E., M.C.l 106 

Watson, T. A., M.C.l .. 457-459 

Wells, E. P., J. P.. P.C.I., 89, 134, 173, 174, 284, 286, mi, 390, 434. 

435, 448, 451, 474. 470, 480, 405, 514, 518, 523, 

531, 550, 561, 502, 563, 505. 372. 573, 374, 573 

Wentworth-Sheilds, F. E., M.Inst.C.E., V.C.P.I., 60, 74, 89, 102, 109, 

277, 296 

Workman, G. C, M.S.E., M.C.I r7, 69, 488, 521, 529, 530 

Yeatman, Morgan E., M.A., .M.Inst.C.E., M.C.L, 169, 170, 212, 241, 

252 
Drawings of Reinforced Concrete Work, The Standardization of ... 75 



Errata ... ... ... ... ... ... ... ... ... ... xv 

Fats, Action of Acids, Oils, and, upon Concrete... ... ... ... 503 

Fireproofing ... ... ... ... ... ... ... ... ... 316 

Fixity, The True Bending Moments of Beams with Various 

Degrees of ... ... ... ... ... ... 132 

High Dams of Great Length 146 

Iron, Concrete, Preserved in ... ... ... ... ... ... xv 

Legal Aspect, Concrete in its 532 

Library, Accessions to xi, xxiii, xxxiii, liii 



vi INDEX 

PAGE 

Masonry Dam, Calculations in the Design of Thrush Buttress ... 299 

Members, Deceased ... ... ... ... ... ix, xxiii 

Membership ... ... ... ix, xxiii, xxxiii, liii 

Meeting, Third Annual General. May o. 1012 .. ... ... ... 262 

Meetings — 

Twentieth Ordinary General Meeting, November 9, 191 1. 
Presidential Address by Sir Henry Tanner, C.B., I.S.O., 

F.R.I.B.A. F.S.I., etc. 1 

Twenty-first Ordinary General Meeting, December 14, iqii. 
Paper by Mr. G. C. Workman, M.S.E.. M.C.I., on "Some 

Recent Works in Reinforced Concrete " 17 

Twenty-second Ordinary General Meeting, January 11, 1912. 
Reading by Mr. R. W. Vawdrey, B.A., Assoc. M.Inst.C.E., 
M.C.I.. of Extracts from Report on ''The Standardization of 

Drawings of Reinforced Concrete Work " 74 

Twenty-third Ordinary General Meeting, February 8, 1012. 111 

Discussion of Paper by Professor Beresford Pite, F.R.I.B.A., 

M.C.I., on " The Esthetic Treatment of Concrete " ... 112 

Twenty-fifth Ordinary General Meeting, April 11, 1012. ... 1 Si 

Paper by Mr. Maurice Behar, M.C.I., entitled "The True 

Bending Moments of Beams with Various Degrees of 

Fixity" ... ... ... ... ... ... 1S2 

Twenty-sixth Ordinary General Meeting, April 25, h>I2. ... 240 

Report of the Tests Standing Committee on the Testing of 
Reinforced Concrete Structures on Completion ... ... 240 

Third Annual General Meeting, May 9, 1912. ... ... ... 262 

Report of Council for 191 1-12 Session 262 

Nineteenth Ordinary General Meeting, October 26. ion ... 316 

Lecture by Mr. Richard L. Humphrey, M.Inst.C.E., 
M.Am.Soc.C.E., President National Association of 
Cement Users, Philadelphia, Pa., entitled " Fireproofing " 316 
Twenty-seventh Ordinary General Meeting, November 14. 1912 403 

Presidential Address by Mr. E. P. Wells, J.P 406 

Twenty-eighth Ordinary General Meeting, November 28, 1912. 435 
Paper by Mr. John M. Theobald, F.S.I. . M.C.I.. entitled 

' Bills of Quantities for Reinforced Concrete " 435 

Twenty-ninth Ordinary General Meeting, December 12, 1012 ... 470 
Continued Discussion on Mr. Theobald's Paper ... ... 480 

Paper by Mr. W. Lawrence Gadd, F.I.C., M.C.I., entitled 

"Action of Acids. Oils, and Fat upon Concrete *' 503 

Thirtieth Ordinary General Meeting, January 9, 1913 531 

Paper by Mr. W. Valentine Ball, Barrister-at-Law, entitled 
" Concrete in its Legal Aspect " 532 

Nigeria, Reinforced Concrete in Southern 397 

Oils and Fats, Acids, Action of, upon Concrete 532 



INDKX 



Papers, Lectures, etc., by 

Mr. G. C. Workman, M.S.E., M.C.I. , entitled "Some Recent 

Works in Reinforced Concrete " ... ••■ ••• ••• 17 

Reading by Mr. R. W. Vawdrey, B.A., Assoc. M. Inst. C.E., 
M.C.I. , of Extracts from Report on " The 'Standardization 
of Drawings of Reinforced Concrete Work " 75 

Interim Report of the Reinforced Concrete Practice Standing 

Committee on the " Consistency of Concrete " 7° 

Professor Beresford Pite, F.R.I. P.. A., M.C.I., entitled "The 

^Esthetic Treatment of Concrete " 112 

Mr. Reginald Ryves, M.Cons.E., Assoc. M.Inst.C.E., M.C.I., 

entitled " High Dams of Great Length " 146 

Mr. Maurice Behar, M.C.I., entitled "The True Bending 

Moment- of Beams with Various Degrees of Fixity " ... 182 

Mr. Reginald Rvves, M.Cons.E., A.M. Inst. C.E., M.C.I., en- 
titled "Calculations in the Design of a Thrust Buttress 
Masonry Dam " 299 

Mr. Richard Humphrey, M.Inst.C.K., M.Am.Soc.C.E., President 
National Association of Cement Users, Philadelphia, Pa., 
entitled " Fireproofing " ... ... ... ... 3 10 

Mr. H. C. Huggins, M.SocE., M.C.I. , entitled "Reinforced 

Concrete in Southern Nigeria"... ... ... 397 

Mr. John M. Theobald, F.S.I., M. C.I. , " Bills of Quantities for 

Reinforced Concrete" ... ... ... 435 

Mr. W. Lawrence Gadd. F.I.C., M.C.I., entitled "Action of 

Acids, Oils, and Fats upon Concrete" 503 

Mr. W. Valentine Ball, Barrister-at-Law, entitled "Concrete in 

its Legal Aspect " 532 

Practice Reinforced Concrete Standing Committee on the Con- 
sistency of Concrete, Interim Report of the ... ... ... 76 

Presidential Addresses 1,406 

Quantities for Reinforced Concrete, Bills of 435 

Reinforced Concrete, Bills of Quantities for 435 

Reinforced Concrete in Southern Nigeria 397 

Reinforced Concrete Practice Standing Committee Reports on 

Standardization of Drawings and Consistency of Concrete ... 76 

Reinforced Concrete, Some Recent Works on ... ... 17 

Reinforced Concrete Structures on Completion, Report of the Tests 

Standing Committee on the Testing of ... 240 

Report of Council, [QII-I2 262 

Report of the Reinforced Concrete Practice Standing Committee on 

the Consistency of Concrete ... ... 7'' 

Report o! Hie lot- Standing Committee on the Testing of Rein- 
forced Concrete Structure- ... ... ... ... ... 240 



viii INDEX 

PAGE 

Southern Nigeria, Reinforced Concrete in 397 

Standardization of Drawings of Reinforced Concrete Work, The ... 75 

Testing of Reinforced Concrete Structures on Completion, Report of 

the Tests Standing Committee on the 240 

True Bending Moments of Beams with Various Degrees of Fixity, 

The - 132 

Visits — 

Works of David Kirkaldy & Son ... ... ... ... ...xxxvi 

London Works of Dorman, Long & Co., Ltd xxxvi 

Premises of J. Sainsbury ... ... ... ... ... ...xxxvi 

H.M. New Stationery Office and H.M. Office of Works Stores xxxviii 
Works of Drew-Bear, Perks & Co., Ltd. ... ... ... ... xxxix 

Works on Metropolitan Railway xliii 



UNW1N BROTHERS, LIMITED, THE GKES1IAM PRESS, WOKING AND LONDON' 






NOTES 



MEMBERSHIP. 



On January 31, 19 12, the Institute had 934 
Members, 15 Students, and 11 Special Subscribers. 



DECEASED MEMBERS. 

The deaths are recorded with regret of Mr. M. G. 
Bradford, Assoc .M. Inst. C.E. (Kmark, Kuching, Sara- 
wak, Borneo) ; and Mr. T. D. Smythe, M.Inst. C.E. 
(Chief Engineer, Chilian State Railways, Santiago, 
Chile). 

MEETINGS. 

The Nineteenth Ordinary General Meeting was held 

on October 26, 191 1, Sir Henry Tanner, C.B., 

I.S.O. (President), in the Chair. 
The Twentieth Ordinary General Meeting was held 

on November 9, 191 1, Sir Henry Tanner, C.B., 

I.S.O. (President;, in the Chair. 
The Twenty-first Ordinary General Meeting was held 

on December 14, 191 1, Sir Henry Tanner, C.B., 

I.S.O. (President), in the Chair. 
The Twenty-second Ordinary General Meeting was held 

on January 11, 191 2, Mr. F. E. Wentworfh- 

Sheilds, M.Inst. C.E. (Vice-President), in the 

Chair. 



The Twenty-seventh Meeting of the Council was held 
on October 26, 191 1, Sir Henry Tanner, C.B., 
I.S.O. (President), in the Chair. 

The Twentieth-eighth Meeting of the Council was held 
on November 9, 191 1, Sir Henry Tanner, C.B., 
I.S.O. (President;, in the Chair. 



x NOTES 

The Twenty-ninth Meeting of the Council was held 
on December 14, 191 1, Sir Henry Tanner, C.B., 
I.S.O. (President), in the Chair. 

The Thirtieth Meeting of the Council was held 
on January 11, 19 12, Sir Henry Tanner, C.B., 
I.S.O. (President), in the Chair. 



The Ninth Meeting of the Finance and General Pur- 
poses Committee was held on October 26, 
191 1, Mr. E. P. Wells, J. P., in the Chair. 

The Tenth Meeting of the Finance and General Pur- 
poses Committee was held on November 9, 
191 1, Mr. E. P. Wells, J. P., in the Chair. 

The Eleventh Meeting of the Finance and General 
Purposes Committee was held on December 14, 
191 1, Mr. E. P. Wells, J. P., in the Chair. 

The Twelfth Meeting of the Finance and General Pur- 
poses Committee was held on Januarv 11, 19 12, 
Mr. E. P. Wells, J. P., in the Chair. 



The Seventh Joint Meeting of the Science and Rein- 
forced Concrete Practice Standing Committees 
was held on December 28, 191 1, Professor 
Henry Adams, M.Inst.C.E., in the Chair. 

The Eighth Joint Meeting of the Science and Rein- 
forced Concrete Practice Standing Committees 
was held on January 4, 1 9 1 2, Professor 
Henry Adams, M.Inst.C.E., in the Chair. 

The Ninth Joint Meeting of the Science and Rein- 
forced Concrete Practice Standing Committees 
was held on January 12, 1 9 1 2, Professor 
Henry Adams, M.Inst.C.E., in the Chair. 

The Tenth Joint Meeting of the Science and Rein- 
forced Concrete Practice Standing Committees 
was held on January 19, 1 9 1 2, Professor 
Henry Adams, M.Inst.C.E v in the Chair. 

The Eleventh Joint Meeting of the Science and Rein- 
forced Concrete Practice Standing Committees 
was held on January 26, 1912, Professor 
Henrv Adams, M.Inst.C.E., in the Chair. 



NOTES xi 

The Twenty -second Meeting of the Science Standing 
Committee was held on November 30, 191 1, 
Professor Henry Adams, M.Inst.C.E., in the 
Chair. 



The Tenth Meeting of the Reinforced Concrete 
Practice Standing Committee was held on 
December 7, 191 1, Mr. E. P. Wells, J. P., in 
the Chair. 

The Eleventh Meeting of the Reinforced Concrete 
Practice Standing Committee was held on 
December 21, 191 1, Mr. E. P. Wells, J. P., in 
the Chair. 



The Sixth Meeting of the Tests Standing Committee 

was held on November 23, 191 1, Mr. W. G. 

Kirkaldv, Assoc. M.Inst.C.E., in the Chair. 
The Seventh Meeting of the Tests Standing Committee 

was held on January 4, 191 2, Mr. E. P. 

Wells, J. P., in the Chair. 

ACCESSIONS TO THE LIBRARY. 

DONATIONS. 

Recent Publications Presented by the Authors. 

(1) "Reinforced Concrete Construction." By 
Henry Adams, M.Inst.C.E., M.I.Mech.E., 
F.S.I., F.R.San. I., and Mr. Ernest R. 
Matthews, Assoc.M.Inst.C.E., F .R .S . (Ed. ), 
F.R.San. I., F.G.S. Published by Long- 
mans, Green & Co., 39, Paternoster Row, 
London. Price 10s. 6d. 

Contents. 

History of " Reinforced Concrete "—General Prin- 
ciples of Stress— Moments of Resistance, Loads and 
Reinforcement — Notation, Formulae and Examples- 
Special Constructions — Effects of Excessive Heat on 
Concrete and Reinforced Concrete — Reinforced Con- 
crete in Municipal Engineering Work — Reinforced 
Concrete in Railway Engineering— Reinforced Concrete 
in Wharves, Jetties, Groynes, Sea Walls, Bins, Fac- 



xii NOTES 

tories, and other Engineering Works — Reinforced Con- 
crete in Building Construction — General Notes. 

The Preface states that although the word " theory " 
is used in the title, the authors have intentionally 
avoided all pure theory, and have included only those 
theoretical principles which are needed to enable the 
necessary calculations in the practical designing of 
such work to be understood. The formulae have been 
reduced to the simplest conditions, and worked 
examples are given so that the merest tyro in mathe- 
matics will have no difficulty in utilising them. The 
illustrations, which are very numerous, are grouped 
under the various branches of construction so that 
any one interested in a particular subject can study a 
variety of typical forms. Many of the illustrations are 
published for the first time. Although there are other 
books dealing with both the theory and practice of 
reinforced concrete construction, there is none, the 
authors state, that takes it quite in the same way, and 
the authors trust that the facility this offers for practical 
use will be found one of its chief recommendations. 



(2) " Reinforced Concrete Compression Member 
Diagram." By Charles F. Marsh, 
M.Inst.C.E., M.Am.Soc.E., M.Inst.M.E. 
Published by Archibald Constable & Co ., 
Haymarket, London, S.W. Price 3s. 6d. 
This consists of several graphs grouped together 
to enable the calculations for the design of hooped 
pillars to be readily performed and the necessary 
dimensions ascertained according to the formulas put 
forward in the Second Report of the Joint Committee 
on Reinforced Concrete appointed by the Royal Insti- 
tute of British Architects, which rules have also been 
adopted in the regulations for the erection of buildings 
ot reinforced concrete in London as drafted by the 
London Countv Council. 



(3) " Tonindustrie Kalender " for 191 2. Published 
by the Tonindustrie Zeitung, Berlin. 

This consists of three parts. Part I. is cloth bound, 
and consists of a Diary with an index of articles. 
Part II. is in paper covers, and contains various 



NOTES xiii 

tables and memoranda. Part III., also in paper covers, 
consists of addresses of firms and other persons, and 
lists of books published in Germany classified under 
various headings. 



141 The London Building Acts, 1894 to 1909: 
Skeleton Frame Buildings (L.C.C. General 
Powers Act, 1909. Part IV.) : Deposit 
of Drawings and Calculations with the 
District Surveyor. Published on behalf 
of the District Surveyors Association by 
Merritt and Hatcher, Ltd., 2, Grocers' 
Hall Court, Poultry, London, E.C. Price 
2s. 6d. net. 

This book contains detailed instructions, tables, and 
diagrams drawn up by the District Surveyors Associa- 
tion, in co-operation with the Royal Institute of British 
Architects and the Surveyors Institution with the object 
that the scheme may be adopted by persons depositing 
with the District Surveyor plans, sections, and calcula- 
tions of steel-frame structures to be erected under the 
provisions of the Act of 1909, as it will manifestly 
be convenient alike to the architect, engineer, and 
district surveyor, for calculations to be submitted upon 
a uniform basis, thus greatly reducing the labour of 
making and checking the calculations. 



g " Y'ersuche mit Eisenbeton-Balken zur ermitt- 
lung der Wiederstandsfahigkeit Ver- 
schiedener Bewehrung gegen Schub- 
krafte." 2nd Part. By Professors C. Bach 
and O. Graf. Published by Wilhelm 
Ernst & Son, Berlin. 

EARLIER PUBLICATIONS. 

Presented by Mr. Edwin O. Sachs, F .R.S.Ed ., Vice- 
President C.I. 

Proceedings of the American Waterworks Asso- 
ciation for the years 1906, 1907, 1908, and 
1909. 



xiv XOTES 

Presented by Indented Bar and Concrete Engineering 
Company, Ltd. 

The Indented Bar Bulletin. Vol. I. August, 
191 1 . 



Presented by Bureau of Standards, Washington, U .S.A. 

Paper by Rudolph J. Wig, Associate Engineer- 
Physicist, on " The Effect of High -Pressure 
Steam on the Crushing Strength of Port- 
land Cement, Mortar, and Concrete." 



Presented by the author, Mr. John Stephen Sewell, 
M.Am.Soc.C .E . 

Papers on " The Economical Design of Reinforced 
Concrete Floor Systems for Fire -resisting 
Structures," and " The Web Reinforcement 
of Concrete Beams." Also, Reports on the 
San Francisco Earthquake and Fire of 
April 18, 1906, by Messrs. Grove Karl 
Gilbert, Richard Lewis Humphrey, John 
Stephen Sewell, and Frank Soule. 



Presented by the University of Illinois. 

Pamphlet entitled, " Tests of Nickel -Steel Riveted 
Producer," by Messrs. C. M. Garland and 
A. P. Kratz. 

Pamphlet entitled, " Tests of Nickel -Steel Riveted 
Joints," by Messrs. Arthur N. Talbot and 
Herbert F. Moore. 



Presented by Messrs. The British Reinforced Concrete 
Engineering Company, Ltd. 

Several copies of 191 1 edition of Catalogue. 







Sketch showing the position oi" Iron Kag Bolt 
found at South Kensington, London. 



NOTES xv 

IRON PRESERVED IN CONCRETE. 

The accompanying illustration is reproduced from 
a sketch sent to the Concrete Institute, together with 
the bolt itself, by Messrs. William King & Son, 
builders, of 5, Vauxhall Bridge Road, West- 
minster, S.W. 

This rag bolt was found, in the summer of 191 1, 
embedded in a slab of concrete composed of Portland 
cement, ballast, and broken bricks, in the position 
shown on sketch. The concrete formed part of the 
foundations of the 1862 Exhibition buildings at South 
Kensington, and had not been disturbed up to the time 
of its removal. The bolt was found when cutting 
through the concrete slab for some alteration in con- 
nection with the Imperial Institute, and was at ground- 
level. A floor had been constructed about 2 ft. above 
this level, so that the concrete and bolt were under 
cover. The bolt sent was one of many found, and 
it was thought they had bolted down machinery. Only 
the top end where exposed to air and the bottom end 
where embedded in soil were corroded ; the remainder 
was quite clean, with the original blue scale thereon. 

ERRATA. 
Volume III. 

It should have been noted on page 273 that among 
the members attending the Annual Dinner on June J > 
191 1, was Mr. E. P. WELLS, J. P. 

On page 252, in the second line from the bottom, 
" Chedame " should be spelt " Chedanne." 



THE CONCRETE 
INSTITUTE 



(FOUNDED 1908. INCORPORATED 1909) 



TRANSACTIONS 

AND 

NOTES 



VOLUME IV PART II 



COPYRIGHT 



Published July, 191 2 

at the Offices of 

THE CONCRETE INSTITUTE, 

Demson House, 296 Vauxhai.i. Bridge Road, Westminster 



OBJECTS OF THE INSTITUTE. 

The objects of the Institute are : — 

(a) To advance the knowledge of concrete and 
reinforced concrete, and other materials employed in 
structural engineering, and to direct attention to 
ihe uses to which these materials can be best applied. 

(b) To afford the means of communication 
between persons engaged in the design, supervision 
and execution of structural engineering works (ex- 
cluding all questions connected with wages and trade 
regulation). 

(c) To arrange periodical meetings for the pur- 
pose of discussing practical and scientific questions 
bearing upon the application and use of concrete 
and reinforced concrete and other materials employed 
in structural engineering for any purpose whatsoever. 



The Institute is not responsible for the views of individual authors 

as expressed in Papers, Letters or Xotes, but only for such 

observations as are formally issued on behalf of the Council. 






COUNCIL. 



President : 

E. P. WO is, J.P 

/'lis/ President : 
Sir Henry i'wm-.k c B..I.S.0 F.R.I.B.A..F S.L.etc. (Principal Archt.H.M. Office of Wort 

Vice-Presidents : 

H. Percy Boulnois, M.Inst.C.E., Cbairmau of Council, R.San. I., etc. ; 

C S. Mi iK, M.Inst.C.E., M I.Mech.E.; 

Edwin O. Sachs, F.R.S Ed., A.Inst.Mech.E., Chairman of Executive B.F.P.C, etc. ; 

P K Wkntworth Sheii ds, M.Inst.C.E. i Dock Engineer, L. .* S. W. Railway) 

Prof. Henry Adams, M.Inst.C.E., M.I.Mech.E., F.S.I., M.S.A., &c. ; 



H. II. I) ANDERSON : 

ii. k. c;. Bauber, k.c.s. : 

Berth \m Blount, F.I.C. ; 

D. B. Butler, Assoc.M.Inst.C.E., F.C.S., PP.S.E.; 

C II. CoLSON, M.Inst.C.E. iSupt. Civil Engineer, Admiralty ; 

A C. 1) wis, Assoc. Insl C.E., K.c.s. ; 

J. S. E. de Visi w M.lnsl C.E, ; 

Alexander Drew, M.I.Mech.E.; 

E. FlANDER ETCH ELLS, F.Phys.Soc., A.M. I.Mech.E. ; 

J. Ernest France, A.R.I.B.A., M.R.San.I.; 

M\u GARB ii. Assoc.M.InsLC.E., F.R.I.B.A. ; 

K. Napier Harvey, Major R.E.; 

Osbokn C. Hills, F.R.I.B.A. (District Surveyor for the Strand); 

William G. Kirkaldy, Assoc.M.Inst.C.E. : 
Charles F. Marsh, M.Inst.C.E., M.I.Mech.E., M.Am.Soc.C.E. ; 

[. MU.VRO : 

W, G. Perkins (District Surveyor for Holborn); 

F. PURTON, F.S.E. ; 

A. ALBAN H. SCOTT, M.S. A. : 

H. D. Sbarles-Wood, F.R.I.B.A., M.R.San.I.; 

LUCIEN SERRAILLIER. ; 

t. b. Shore -, 

Henry Tanner, F.R.I.B.A. ; 

H. J. Tingle, M.Inst.C.E. ; 

R. \V. Vawdrey, B.A., Assoc.M.Inst.C.E.; 

G. c. Workman, M.S.E. 



Hankers : 

PARR'S BANK, LTD., 

Charing Cross, London, W.C. 

Offices : 
Denison House, 
.■>/'. Vauxhall Bridge Road, Westminster. 



Secretary: II. Kempton I 



FINANCE AND GENERAL PURPOSES 
COMM5TTEE. 

Mr. H. D. Searles-Wood, F.R.I. B.A., Chairman. 

Mr. Edwin O. Sachs. F.R.S.Ed. Mr. G. C. Workman, M.S.E. 

Sir Henry Tanner, C B., I.S.O., F.R.I.B.A., F.S.I. 

Ex-officio: President and Chairmen of Standing Committees. 

STANDING COMMITTEES . 

SCIENCE STANDING COMMITTEE : 
Prof. Henry Adams, M.Inst.C.E., Chairman. 
Mr. E. Fiander Etchells, F.Phys.Soc, I ice-Chairman. 
Mr. H. K. G. Bamber, F.C.S. Mr. Chas. F. Marsh, M.Inst.C.E , M.Am.Soc C.E 

Mr. Bertram Blount, F.I.C. Mr. C. S. Meik, M.Inst.C.E. 

Mr. William Dunn, F.R.I.B.A. Mr. H. D. Searles-Wood, F.R.I. B.A. 

Mr. J. E. Franck, A.R.I. ISA. Mr. F. E. Wentworth-Sheilds, M.Inst.C.E. 

Mr. William G. Kirkaldy, Assoc. M. Inst. C.E. Mr. M. E. Yeatman, M.A., M.Inst.C.E.. 

M.Am.SocC.E. 
Mr. R. W. Vawdrey, BA., Assoc.M.Inst.C.E. Hon. Secretary. 

PARLIAMENTARY STANDING COMMITTEE : 
Mr. H. Percy Boulnois, M.Inst.C.E., Chairman. 
Mr. W. H. Johnson. B Sc. Vice-Chairman. 
Mr. H. H. D. Anderson. T. de Courcy Meade, M.Inst C.E 

Mr. J. S. E. de Vesian, M.InstC.E. Mr. W. G. Perkins. 

Mr. Matt Garbutt. Assoc.M.Inst.C.E., Edwin O. Sachs, F.R.S.Ed., etc. 

F.R.I.B.A. Mr. L. Serraillier. 

Mr. Osborn C. Hills, F.R.I B.A. Mr. Henry Tanner, Junr. F.R.I.B.A. 

Mr. J. Ernest Franck, A. R.I. B.A. , Hon. Secretary. 

REINFORCED CONCRETE PRACTICE STANDING COMMITTEE 
Mr. Alexander Drew, M.I.Mech.E., Chairman. 
Mr. Ewart S. Andrews, B Sc. (Lond.). Mr. P. W. Leslie. 

Mr. F. Bradford. Mr. F. Purton, F.S.E. 

Mr. S. Bylander. Mr. L. H. Rugg, Assoc.M.Inst.C.E. 

Mr. J. S. E. de Vesian. M.Inst.C.E. Mr. T. B. Shore. 

Mr. Oscar Faber, B.Sc (l.ond.). Mr. R. T. Surtees. 

Mr. Moritz Kahn. Mr. T. A. Watson, Assoc.M.Inst.C.E. 

Mr. G. C. Workman. MlS.E.. Hon. Secretary. 

TESTS STANDING COMMITTEE : 
Mr. William G. Kirkaldy, Assoc. M. Inst C.E.. Chairman. 
Mr. Alexander Drew. M.I.Mech.E., Vice-Chairman. 
Mr. II. K. G. Bamber, F.C.S. Mr. Edward Dru Drury, F.R.I.B.A. 

Mr. Bertram Blount, F.I.C. Mr. P. M. Fraser, A.R.I. B.A. 

Mr. 1). B. Butler, Assoc.M.Inst.C.E. Major R. Napier Harvey, R.E. 

Mi". A. C. Divis. Assoc.Inst.CE , F.C.S. Mr. William F. King. 

Mr. R. H. Harry Stanger, Assoc.M.Inst.C.E. 
Mr. A. Albau II. Scott, M.S.A., Hon. Secretary. 



■A-0 



CONTENTS 



N es— PAGE 

Membership xxiii 

Deceased .Member xxiii 

Accessions to the Library ... ... ... ... ... ... xxiii 

rwenty-third Ordinary General Meeting, February 8, iqi2... ... in 

Discussion of paper by Professor 1'ite on " The .-Esthetic Treat- 
ment of Concrete"... ... ... ... 112 

Twenty-fourth Ordinary General Meeting, March 14, 1912 ... ... 145 

Paper by Mr. Reginald Ryves, AssocM.Inst.CE, M.C.I., on 
" High Dams of Great Length " 146 

Twenty-fifth Ordinary General Meeting, April 1 r, 1912 1S1 

Paper by Mr. Maurice Behar entitled '• The True Bending 
Moments of Beams with various Degrees of Fixity " 182 

Twenty-sixth Ordinary General Meeting, April 25, 191 2 240 

Report of the Tests Standing Committee on the Testing of 

Reinforced Concrete Structures on Completion ... ... 240 

Third Annual General Meeting, May 9, 1012 262 

Report of Council for 191 1-1 2 Session 262 

The Second Annual Dinner. May 9, 1912 ... ... ... ... 288 

Discussion at Meeting- : Participation therein by — 

ns, Henry, M.Inst.C.E., M.C.I. ... 203, 209, 254, 255, 260 

Andrews, Ewart S., B.Sc. (Lond.) [64,210 

Behar, Maurice, M.C.I. 170, 228 

Bolton, Arthur T., K.R.I. B. A 127,137 

Butler. D. B., A -oc. M.Inst.C.E., F.C.S., M.C.I. 244 

Bylander, S., M.C.I 170 

Bulnois, H. Percy, M.Inst.C.E., V.P.C.l 276 

Bungard, Arthur William, Lic.R.I.B.A., M.C.I 251 

Dudley, R., Assoc. M.Inst.C.E 172,173 

Etchells, E. Piander, F.Phys.Soc, M.C.I. 137, [66, [68, 223, 237 

Fraser, Percival M., A.R.I.B.A., M.C.I 247 

Holman, G. K. ... ... ... ... ... ... ... ... 297 

Kirkaldy, William <; . A .M.Inst.C.E., M.C.I. ...242, 2^,2, 285 

Marsh, Charles F., M.I nst C.E., M.C.I 161 

Perkins, \V.. M.C.I 172 

xxi 



XXII 



CONTENTS 



Pite, Beresford... 

Roberts, George S., M.C.I 

Robertson, D. Webster, M.C.I. 

Riley, W. E 

Ryves, Mr. 

Sachs, Edwin O., V.P.C.I., F.R.S.Ed. 

Scott. A. Alban H., M.S. A., M.C.I. 

Serraillier, Lucien, M.C.I. 

Shepherd. Herbert, A.R.I. B. A., M.C.I. 

Sinclair, R. X.. M.C.I 

Solly, J. K. Travels, Assc.M.Inst.C.E., M.C.I. 
Steinberg, Herbert E.. Assoc. M.lnst.C.E., M.C 
Tanner, Sir Henry, C.B., I.S.O., F.R.I. B.A., F. 



I. 
S.I.. 



141, 



1/4, 



134, 
280 



Trechmann, A. O.. F.C.S., M.C. I.... 

Vawdrev, R. W., B.A.. AsMjc.M.Inst.C.E.. M.C.I. ... 

Wells, E P., J. P., M.C.I I34.l73i 

Wentworth-Sheilds, F. E., M.InstC.E., V.P.C.I. 
Yeatman, Morgan E., M.A.. M.Am.Soc.C.E., M.C.I, 



174 



PAGE 
282 

253 
2l6 
290 
179 
274 
257.25X. 28S 

!4°, 275 

I3S, 139 

246 

... 250 

217 

I40, 273, 278, 

28 1, 284, 286 

245. 254 

206, 209 

284, 286, 293 

277. 296 

169, 170, 212, 
241, 25 2 



>.< I> I 



NOTES 

MEMBERSHIP. 

On June 30, 191 2, the Institute had 878 Members, 
23 Students, and 9 Special Subscribers. 

DECEASED MEMBER. 

Mr. William James Watson, J.P., M.R.A.I., F.S.I., 
nue, Rostrevor, Co. Down. 



ACCESSIONS TO THE LIBRARY. 

DONATIONS. 

Rei i.\i I'i blications Presented by the Authors 
and Publishers. 

111 " Reinforced Concrete Buildings." By Mr. 
Ernest L. Ransome, Assoc. Am. Soc.E., 
Charter Member W. Soc.E., Hon. Corres. 
Member R.I.A., Member Royal Society of 
Arts, etc., and Mr. Alexis Saurbrey, 
Assoc. M. Am. Soc.C.E., Member Dansk 
Ingenior Forening, etc. Published by the 
McGraw-Hill Book Company, 6, Bouverie 
Street, London, E.C. 

Elementary Principles of Reinforced Con- 
crete Construction." By Mr. Ewart S. 
Andrews, B.Sc.Eng. (Lond.). Published by 
Scott, Greenwood & Son, 8, Broadway 
Ludgate, E.C. 



xxiv XOTES 

(3) " ^ ersuche iiber die Widerstandsfahigkeit von 

Beton und Eisenbeton gegen Yerdrehung." 
By Professors C. Bach and O. Graf. Pub- 
lished by Wilhelm Ernst & Sohn, Berlin. 

(4) " Priifung von Balken zu Kontrollversuchen." 

By Professors C. Bach and O. Graf. Pub- 
lished by Wilhelm Ernst & Sohn, Berlin. 

(5) " Untersuchungen an durch laufenden Eisen- 

betonkonstruktionen." With 52 illustra- 
tions. By Professors H. Scheit and E. 
Probst. Published by Julius Springer, 
Berlin. 

Presented by the Author, Monsieur Ic Chatelier, Paris. 

(1) Two pamphlets entitled "Decomposition des 

Ciments a la Mer." 

(2) One pamphlet entitled " L'Industrie des Pro- 

duits Hydrauliques dans ses Rapports avec 
la Science." 

(3) One copy " Essais des Materiaux Hydrau- 

liques." 

(4) Chronique, " Appareil Hydrauliques." 

(5) One pamphlet entitled " Tests of Hydraulic 

Materials." In English. 

(6) One pamphlet entitled " L'Industrie des 

Ciments et des chaux Hydrauliques devant 
les Consommateurs." 

(7) Six small pamphlets on various subjects. 

Presented by the Paint and Varnish Society. 

Paper entitled " The Protection and Finishing of 
Concrete Surfaces." By Mr. Robert Cath- 
cart, Cleveland, Ohio, U.S.A. 

Presented by the Author, Mr. H. St. George Robinson. 
Paper entitled " The Lateral Pressure of Liquid 
Concrete." 

Presented by the Author, Mr. J. Richard Gwy titer, 
M.A. 
Four copies of a paper entitled " The Modes of 
Rupture of an Open Hemispherical Concrete 
Shell under Axial Pressure." 



NOTES xxv 

F resented by the British Ceresit Water Proofing Com- 
pany, Ltd. 
Seven pamphlets entitled " Ceresit and its Uses in 
all Building Operations." 

Presented by the University of Illinois. 

Several copies of pamphlets entitled : — 
. i ' " rests on Columns, etc." By .Messrs. 
Arthur N. Talbot and A. R. Lord. 

(2) "Starting Currents of Transformers." By 

.Mr. Trygoe de Vensen. 

(3) "Mechanical Stresses in Transmission 

Lines." By Mr. A. Guell. 
(41 " An Investigation of the Strength of Rolled 

Zinc." By Mr. Herbert F. Moore. 
(5) "Street Lighting." By Messrs. J. M. 

Bryant and H. C. Hake. 
" Inductance of Coils." By Messrs. Morgan 

Brooks and H. M. Turner. 

Presented by the American Society of Mechanical 
Engineers. 

Copies of Proceedings of the Society for Decem- 
ber, 191 1, January, 191 2, February, 191 2, 
March, 191 2, April, 191 2, and May, 191 2. 

Presented by the Liverpool Engineering Society. 

Copy of the Proceedings of the Society for the 
1910-1 1 Session. 

Presented by the Engineers" Society of Western Penn- 
sylvania. 

Copies of the Proceedings of the Society for 
December, 191 1, January, 191 2, February, 
19 1 2, March, 19 12, and April, 191 2. 

Presented by the Cleveland Engineering Society, 
Cleveland, Ohio. 

Copy of Transactions for 1 908 and copies of the 
Journal for September and December, 1909, 
March, June, September, and December, 
1 9 1 o, March, June, September, and Decem- 
ber, 1 9 1 1 . 



NOTES 



Presented by the Executive Committee of the Per- 
manent International Association of Road 
Congresses . 

( i ) List of Members. 

(2) Copy of Bulletin for March, 19 12. 

Presented by the Executive Committee of the Twelfth 
International Congress of Navigation, Phila- 
delphia. 

Copy of February, 191 2, Bulletin. 

List of Members. 

Four bound volumes of papers contributed to 
Sections I. and II. of the Twelfth Inter- 
national Congress of Navigation, Phila- 
delphia. 

The following Journals are also sent gratuitously by 
the Publishers: — 

The Architect." 

The Builder.'* 

Cement -Age." 

Concrete and Constructional Engineering." 

Engineering." 

Engineering News." 

Engineering Record." 

Ferro-Concrete." 

The Indented Bar Bulletin." 

Page's Weekly." 

Southern Builder and Engineer." 

The Surveyor." 

Tonindustrie-Zeitung." 



THE CONCRETE 
INSTITUTE 

AN INSTITUTION FOR STRUCTURAL ENGINEERS, 
ARCHITECTS, ETC. 



[FOUNDED 1908. INCORPORATED 1909) 



TRANSACTIONS 

AND 

NOTES 



VOLUME IV : PART III 



COPYRIGHT 



Published December, 1912 

at the Offices of 

THE CONCRETE INSTITUTE, 

Demson House, 296 Vauxhall Bridge Road, Westminster 



OBJECTS OF THE INSTITUTE. 

The objects of the Institute are : — 

(a) To advance the knowledge of concrete and 
reinforced concrete, and other materials employed in 
structural engineering, and to direct attention to 
the uses to which these materials can be best applied. 

(b) To afford the means of communication 
between persons engaged in the design, supervision 
and execution of structural engineering works (ex- 
cluding all questions connected with wages and trade 
regulation). 

(c) To arrange periodical meetings for the pur- 
pose of discussing practical and scientific questions 
bearing upon the application and use of concrete 
and reinforced concrete and other materials employed 
in structural engineering for any purpose whatsoever. 



The Institute is not responsible for the views of individual authors 

as expressed in Papers, Letters or Notes, but only for such 

observations as are formally issued on behalf of the Council. 



■ 



COUNCIL. 



President : 
E. P. Wells, jr. 

Post President : 
Sir Henry Tanner, C.l ;.. I SO.. F.R.I.B.A.,F.S.I..etc. (Principal Archt.H.M. Office of Works). 

Vice-Presidents : 

H. Percy BOULNOIS, M.Inst.C.E., Chairman of Council, R.San. I., etc. ; 

C S. Meik. M.Inst.C.E.. M.I.Mech.E. ; 

EDWIN O. SACHS, F.RS.F.d., A.Inst.Mech F . Chairman of Executive B.K.P.C, etc. : 

F E. Wextworth-Shkii.ds. M.InstC.E. (Dock Engineer. L. tt S. W. Railway) 

Prof. HENRI Adams. M.Inst.C.E.. M.I.Mech.E., F.S.I. . M.S.A., Sc. : 



H. H. D. Anderson ; 

H. K. G. BAMBER, F.C.S. : 

Bertram Blount, K.I.C. ; 

D i; Butler, AssocM.Inst.CE., F.C.S., PP.S.E.; 

C H. Col-SON. M.Inst.C.E. (Supt Civil Engineer. Admiralty : 

A. c. Davis, Assoc.Inst.CE, F.C.S. : 

J. s. F. de Visian, M.Inst.C.E.; 

Alexander Drew. M.I.Mech.E.; 

E. FlANDER ETCH ELLS, F.Phys.Soc., A. M.I.Mech.E. : 

f. Ernest France, A.R.I.B.A., M.R.San.I. ; 

Matt Garbltt. AssocM.Inst.CE., F.K.I. B.A. : 

R. N"\pier Harvey, Major R.F. ; 

Osborn C. Hills, F.R.I. B.A. (District Surveyor for the Strand) ; 

William G Kirk.ai.DY, Assoc. M.Inst.C.E. : 
Charles F. Marsh, M.Inst.C.E., M.I.Mech.E., M.Am.Soc.C.E. 

J. Ml'NRO : 

W. G. Perkins (District Surveyor for Holborn) ; 

F. P0RTON, F.S.E. : 

A. Alban H. Scott, M.S.A. ; 

H. D. SEARLES-WOOD, F.R.I. B.A. , M.R.San.I. ; 

Lucien Serrau.lier. ; 

T. B. shore ; 

Henry Tanner. F.R.I. B.A. ; 

H. j. Tingle, M.inst.c.K. ; 

R. W, VAWDREY, B.A., AssocM.Inst.CE. ; 
G. c. Workman, M.S.E. 



Hankers : 

PARR'S BANK. LTD., 

Charing Cross, London, W.C 

Offices : 
Denison House, 
296, Vauxhall Bndge Road, Westminster. 



Secretary: H. Kempton Dyson. 



FINANCE AND GENERAL PURPOSES 
COMMITTEE. 

Mr. H. D. Searles-Wood, F.R.I. B.A., Chairman. 

Mr. Edwin O. Sachs, F.R.S.Ed. Mr. G. C. Workman, M.S.E. 

Sir Henry Tanner, C.B., I.S.O., F.R.I. B.A., F.S.I. 

Ex-officio : President and Chairmen of Standing Committees. 

STANDING COMMITTEES . 

SCIENCE STANDING COMMITTEE: 
Prof. Henry Adams, M.Inst.C.E., Chairman. 
Mr. E. Fiander Etchells, F.Phys.Soc, Vice-Chairman. 
Mr. H. K. G. Bamber, F.C.S. Mr. Chas. F. Marsh, M.Inst.C.E , M.Am.Soc.C.E. 

Mr. Bertram Blount, F.I.C. Mr. C. S. Meik, M.Inst.C.E. 

Mr. William Dunn, E.R.I.B.A. Mr. H. D. Searles-Wood, F.R.I. B.A. 

Mr. J. E. Franck, A.R.I. B.A. Mr. F. E. Wentworth-Sheilds, M.Inst.C.E. 

Mr. William G. Kirkaldy, Assoc.M.Inst.C.E. Mr. M. E. Yeatman, MA.. M.Inst.C.E., 

M.Am.Soc.C.E. 
Mr. R. W. Vawdrey, B A., Assoc.M.Inst.C.E., Hon. Secretary. 

PARLIAMENTARY STANDING COMMITTEE: 
Mr. H. Percy Boulnois, M.Inst.C.E., Chairman. 
Mr. W. H. Johnson, B Sc. Vice-Chairman. 
Mr. H. H. D. Anderson. T. de Courcy Meade, M.Inst.C.E. 

Mr. J. S. E. de Yesian, M.Inst.C.E. Mr. W. G. Perkins. 

Mr. Matt Garbutt, Assoc.M.Inst.C.E., Edwin O. Sachs, F.R.S.Ed., etc. 

F.R.I. B.A. Mr. L. Serraillier. 

Mr. Osborn C. Hills, F.R.I. B.A. Mr. Henry Tanner, Junr., F.R.I. B.A. 

Mr. J. Ernest Franck, A. R.I. B.A. , Hon. Secretary. 

REINFORCED CONCRETE PRACTICE STANDING COMMITTEE 
Mr. Alexander Drew, M.I.Mech.E., Chairman. 
:Mr. Ewart S. Andrews, B Sc. (Lond.). Mr. F. Purton, F.S.E. 

Mr. F. Bradford. Mr. L. H. Rugg, Assoc.M.Inst.C.E. 

Mr. S. Bylander. Mr. T. B. Shore. 

Mr. Oscar Faber, B.Sc. (Lond.). Mr. R. T. Surtees. 

Mr. Moritz Kahn. Mr. T. A. Watson, Assoc.M.Inst.C.E. 

Mr. P. W. Leslie. 

Mr. G. C. Workman, M.S.E., Hon. Secretary. 

TESTS STANDING COMMITTEE: 
Mr. William G. Kirkaldy, Assoc. M.Inst C.E., Chairman. 
Mr. Alexander Drew, M.I.Mech.E., Vice-Chairman. 
Mr. H. K. G. Bamber, F.C.S. Mr. Edward Dru Drury, F.R.I. B.A. 

Mr. Bertram Blount, F.I.C. Mr. P. M. Eraser, A.R.I. B.A. 

Mr. D. B. Butler, Assoc.M.Inst.C.E. Major R. Napier Harvey, R.E. 

Mr. A. C. Davis, Assoc.Inst.C.E., F.C.S. Mr. William F. King. 

Mr. R. H. Harry Stanger, Assoc.M.Inst.C.E 
Mr. A. Alban H. Scott, U.S.A., Hon. Secretary . 






CONTENTS 



Notes— ''age 

Membership ■•■ ••• ••• xxxiii 

Accessions to the Library xxxiii 

Visits — 

Works of David Kirkaldy & Son xxxvi 

London Works of Dorman, Long & Co., Ltd xxxvi 

Premises of J. Sainsbury xxxvi 

H.M. New Stationery Office and H.M. Office of Works Stores xxxvi i 

Works of Drew-Bear, Perks & Co., Ltd xxxix 

Works on Metropolitan Railway ... ... ... ... ... xliii 

Meeting, March 14, 191 2 

Paper by Mr. Reginald Ryves, M.Cons.E., Assoc.M.Inst.C.E., 
M.C.I.. entitled "Calculations in the Design of a Thrust 

Buttress Masonry Dam"... ... ... ... 299. 

Nineteenth Ordinary General Meeting, October 26, 1911 316 

Lecture by Mr. Richard Humphrey, M.Inst.C.E., M.Am.Soc.C.E., 
President National Association of Cement Users, Philadelphia, 

Pa., entitled " Fireproofing." ... ... ... ... ... 3 IO> 

Discus-ion at Meetings : Participation therein by — 

Etchells, E. Fiander, F.Phys.Soc, M.C.I. (Council) 3S7 

Humphrey, Mr. 392 

Kirkaldy, William G., Assoc.M.Inst.C.E., M.C.I 390 

Sachs, Edwin O., F. R.S.Ed. (Vice-President Concrete Institute) 383 

Tanner, Sir Henry (Chairman) 392 

Wells, E. P., J. P. (Treasurer), (Council) 39» 



NOTES 



MEMBERSHIP. 

Ox December 12, 191 2, the Institute had 906 
.Members, 34 Students, and 7 Special Subscribers. 

ACCESSIONS TO THE LIBRARY. 

DONATIONS. 

Recent Publications Presented by the Authors 
and Publishers. 

(1 i " Reinforced Concrete Construction." Vol. I. 
By George A. Hool, S.B., Associate Pro- 
fessor of Structural Engineering at the 
University of Wisconsin. Published by 
the McGraw-Hill Book Company, 6, Bou- 
verie Street, London, E.C. 

(2) " Concrete Steel Construction." Part I. By 
C. A. P. Turner, M.Am.Soc.C.E., Con- 
sulting Engineer. Published by the 
Farnham Printing and Stationery Com- 
pany, Minneapolis, Minnesota. 

(3 1 Pamphlet : " The Turner Mushroom System." 
By C. A. P. Turner, M.Am.Soc.C.E. 

(4) "Estimating for Reinforced Concrete." By 
Major T. E. Coleman, Staff for Royal 
Engineer Services. Published by B. T. 
Batsford, 94, High Holborn, W.C. 



xxxiv NOTES 

Presented by the Authors, Professor C. Bach and 
O. Graf. 

(i ) Versuche mit Eisenbetonbalken zur Ermitt- 
lung Widerstandsfahigkeit Verschiedener 
Bewehrung gegen Schubkrafte (Dritle 
Teil). 

(2) Mitteilungen iiber Forschungsarbeiten 

Presented by the Engineering Standards Committee . 

Copy of " British Standard Specification for 
Structural Steel for Bridges and General 
Building Construction." 

Presented by the Government Printing Office, 
Washington . 

(1) Copy of Technologic Papers of the Bureau 

of Standards : " Tests on Reinforced 
Concrete Beams." By Richard L. Hum- 
phrey and H. Losse. 

(2) Copy of paper, " Portland Cement Mortars 

and their Constituent Materials." By 
Richard L.Humphrey and W. Jordan, jun. 

Presented by the Association of American Portland 
Cement Manufacturers. 

Ten pamphlets as follows : — 

(1) The Concrete Review. Vol. IV., No. 6. 

(2) " Concrete Surface Finish." By A. D. F. 

Hamlin . 

(3) " Reinforced Concrete Chimneys." By 

Sanford E. Thompson, M.Am.Soc.C.E. 

(4) " The Use of Cement in Sewer Pipe and 

Drain Tile Construction." 

(5) " Concrete Silos." By C. W. Gayford and 

P. H. Wilson, M.Am.Soc.C.E. 

(6) " Cement Stucco." By J. T. Simpson, C.E. 

(7) " Concrete Tanks." By J. T. Simpson, C.E. 

(8 ) " Concrete in the Counting." By J. T. 

Simpson, C.E. 

(9) " Concrete School Houses," etc. By J. T. 

Simpson, C.E. 
(10) " Concrete Highways." 



NOTES xxxv 



Presented by Mr. Hubert C. Sands. 

Copies of the Proceedings of the Surveyors' 
Institution, from the year 1902 to the 
year 191 1 (4 bound volumes). 

Presented by the Permanent International Association 
of Road Congresses . 

Four copies of the Bulletin . 

Presented by the Permanent International Association 
of Navigation Congresses. 

Six pamphlets in reference to Congresses. 

The following Journals are also sent gratuitously by 
the various Institutions and Publishers : — 

Journal of the Royal Institute of British Archi- 
tects 
„ „ Society of Architects. 

„ „ Surveyors' Institution. 

„ „ Institution of Technical En- 

gineers . 
„ „ American Society of Civil En- 

gineers. 
„ „ Architectural Association. 

„ „ Society of Engineers. 

„ „ Royal Society of Arts. 

„ „ Institution of .Municipal En- 

gineers. 
„ „ American Society of Mechanical 

Engineers. 
„ „ Institute of Chemistry of Great 

Britain and Ireland. 
„ „ Engineers' Society of Western 

Pennsylvania. 
The Architect and Engineer of California." 
" The Architect." 
" The Builder." 
" Concrete-Cement Age." 

" Concrete and Constructional Engineering." 
1 " Engineering." 

" Engineering News." 



xxxvi NOTES 

Engineering Record." 

Ferro-Concrete ." 

The Indented Bar Bulletin." 

Machinery." 

Page's Weekly." 

Southern Builder and Engineer." 

The Surveyor." 

Tonindustrie-Zeitung ." 

VISITS. 

Works of David Kirkaldy and Son. 

By the courtesy of Mr. William G. Kirkaldy, Assoc. 
M.Inst.C.E. (Member), members of the Concrete 
Institute visited the Testing and Experimenting Works 
of Messrs. David Kirkaldy and Son,' of 99, South - 
wark Street, London, S.E., on Saturday, July 20, 191 2. 
For convenience the party was limited to twenty in 
number . 

London W t orks of Dorman, Long & Co., Ltd. 

By the courtesy of Messrs. Dorman, Long & Co., 
Ltd., the members of the Concrete Institute visited the 
Works of this firm on Wednesday, July 24th, at Nine 
Elms Lane, London, S.W. The works of Messrs. 
Dorman, Long & Co. are for the manufacture of 
structural steelwork. 

Premises of J. Sainsbury. 

By the courtesy of Mr. A. Sykes, F.R.I.B.A., the 
members of the Concrete Institute visited a warehouse 
in course of construction for Mr. J. Sainsbury, situate 
at the corner of Bennett and Stamford Streets, close 
to Blackfriars Bridge, London, S.E., on Saturday, 
September 7, 19 12. 

This warehouse, which measures approximately 
165 ft. long by 54 ft. wide, comprises six floors 
and roof. With the exception of the elevations to 
Bennett Street and Stamford Street the whole skeleton 
is constructed in reinforced concrete, lintels being pro- 
vided in the outside walls to carry the brickwork, which 
has a thickness of 2 ft. 3 in. at the bottom. The 



NOTES xxxvii 

Ulterior columns had to be kept down to as small a 
size a> possible, and to carry the six floors heavily 
Loaded a large percentage of steel was necessary, one 
of the lower columns requiring nearly 40 sq. in. In 
the ground floor three loading docks, 24 ft. by 20 ft. 
and 4 ft. 5 in. below ground-floor level, have been 
provided, each designed to carry a 10-ton axle load. 
Each floor consists of a 4^ -in. slab carried on 
secondary beams 5 ft. to 6 ft. apart. This 4^ -in. 
floor is composed of 3^ in. of 6 to 1 concrete and 

I in. nt granite finish, laid simultaneously with the 
concrete. The secondary beams are 14 in. deep below 
-lab and 7 in. wide, and have spans varying from 

II ft. to 15 ft. 5 in. The secondaries are carried 
on main beams 18 in. below slab, and 10 in. and 
S in. in width ; the span of the main beams varies 
from 12 ft. to 22 ft. 6 in. 

Another interesting feature in this work is the retain- 
ing wall and vaults below the road in Bennett Street 
and Stamford Street. To carry the heavy road traffic 
in Bennett Street a superload of 10 cwts. per square 
foot was allowed on the roof of the vaults, and a 
corresponding lateral pressure on the retaining wall, 
and the lateral thrust on the building had to be 
carefully provided for. 

The foundations are composed partly of independent 
footings to columns and partly of strip footings of 
various lengths and widths. Some trouble was experi- 
enced with the ground, and the foundations had to 
be carried lower down than at first intended, and in 
one case piles had to be driven to a depth of 12 ft. 
below foundation level. 

The reinforcement throughout is " indented " steel 
bars, supplied by the Indented Bar and Concrete 
Engineering Company, Ltd., who are responsible for 
the engineering design of the reinforced concrete con- 
struction. 

II. M. New Stationery Office and H.M. Office 
of Works Stores. 

By the courtesy of Sir Henry Tanner, C.B., I.S.O., 
F.R.I.B.A., Principal Architect of H.M. Office <>t 
\\'<»rk- fPast President of the Concrete Institute 1, the 



xxxviii NOTES 

members of the Concrete Institute visited H.M. New 
Stationery Office and H.M. Office of Works Stores, in 
course of construction on a site abutting on Waterloo 
Road and Stamford Street, London, S.E. The entrance 
to the site is in Cornwall Road. 

The new structure will be in two blocks, the larger, 
in Stamford Street, being the warehouse, and the 
smaller one, facing Waterloo Road, being the office 
portion. 

A short street, Bazon Street (formerly Bond Street >, 
separates the two portions, but they will be connected 
from the level of the first floor and upwards by arched 
beams of 2 8 -ft. span, carrying a building 40 ft. wide 
and forming additional space for the offices. 

The following give the general dimensions : — 

Length of frontage to Stamford Street ... 323 ft. 

„ „ Cornwall Road ... 189 ft. 

„ ,, Doon Street ... ... 377 ft. 

„ „ Waterloo Road ... 106 ft. 

Average height of main fronts above footpath yj ft. 

Including ground floor and basement, there will be 
seven floors in the warehouse and eight floors in the 
office block, including sub -ground and basement. 

The height, generally, from floor to floor will be 
11 ft. in the office block and 10 ft. 6 in. in the 
warehouse. 

The total floor area to be provided by the present 
contract is 380,000 ft. super, but the contemplated 
addition of a fifth floor and an extension over the 
remainder of the site will provide a further 100,000 
superficial ft., or a total of roughly 1 1 acres for the 
complete scheme. 

Internal areas, of which there will be two in the 
office block and three in the warehouse, will be pro- 
vided to light the interior parts of the building. The 
windows of the warehouse will be provided with steel 
sashes. 

The working of the warehouse will be carried on 
mainly by means of eight electric lifts for goods at 
the platform of the loading-yard in Doon Street. 
There are also two lifts for passengers, one for the 
offices and one for the warehouse. 



NOTES xxxix 

For the office staff a dining-room, ^ ft. by 23 ft., 
will be provided on the top floor of the office building, 
ther with kitchens, etc., specially fitted with steam 
and other cooking arrangements. In connection with 
this part a goods lift is provided for stores and for 
service at all floors from basement. 

The drains inside the building will be of cast-iron 
pipes, laid under the basement floor. 

A < omplete system of heating by hot water under 
forced circulation will be provided. 

The reinforced concrete work is being carried out 
on the Hennebique system, the drawings for the re- 
inforced concrete work being prepared by Messrs. L. G. 
Mouchel and Partners, Ltd. Messrs. Perry & Co., 
Ltd., of Bow, are the contractors. The following 
independent floor loads are allowed for : — 

In warehouse, ground floor ... 3 cwt. per sq. ft. 

„ other floors ... 2|cwt. „ 

In offices, all floors ... ... 100 lbs. „ 

In roofs ... ... ... 65 lbs. „ 

The floor slabs are 3^ in. thick in warehouse and 

3 in. thick in offices. ~ External walls generally are 

4 in. and 6 in. thick. The boiler chimney will be 
also of reinforced concrete, 4 ft. 3 in. sq. .inside, 
1 10 ft. in height, with sides 7 in. thick at bottom 
and 5 in. thick at top. It will be lined throughout with 
firebrick, set 3 in. clear of sides, and built in sections, 
supported by corbelling. All columns have octagonal 
bases designed to distribute a pressure not exceeding 
3 tons per square foot on the foundation. 

The front of office block facing Waterloo Road will 
be of Portland stone, carried by the reinforced con- 
crete columns and beams, mainly at level of sub- 
ground floor. This, together with all joinery, plumbing, 
and other finishing work, will be carried out under a 
--■parate contract. 

Works of Drew-Bear, Perks & Co., Ltd. 

By the courtesy of Messrs. Drew-Bear, Perks & 
Co., Ltd., the members of the Concrete Institute visited 
their Battersea Steel Works on Wednesday, October 9, 
191 2. 



xl XOTES 

The entrance of the works is in Wellington Road, 
Battersea Bridge, London, S.W. 

The following is a general description of the Steel 
Works :— 

These works are specially laid out for the manufac- 
ture of steel stanchions, girders, beams, etc., for 
buildings, roof-work of all descriptions, and light 
bridge -work. 

The works are driven throughout — with the excep- 
tion of a few hydraulic machines — by electric power. 
The current, at 460 volts, is generated on the premises 
by means of : — 

1. The prime mover : a gas-engine of 130 h.p., 

supplied by producer gas from a pressure - 
gas plant. 

2. Two electric dynamos, which are belt -driven 

from the engine flywheels. 

The hydraulic power is supplied by motor -driven 
pumps working to an accumulator, which delivers water 
to the machines at a pressure of 1,500 lbs. per square 
inch. 

In the main workshop bay, which has a length of 
250 ft. by 40 ft. span, the first machines we come 
to are two gangs each of 4 -radial drilling-machines. 
Each gang is driven by an electric motor in a pit 
working a horizontal shaft in a trench under the 
machines. The machines have 6-ft. arms and turn 
a complete circle. High-speed steel -twist drills are 
used with spindle speeds varying from 170 to 270 
revolutions per minute. 

There is also a 6-ft. wall radial drill for odd work. 

The next machine is an " Ender," also motor-driven. 
This machine has a self-feeding rotating head, fur- 
nished with two high-speed steel -cutter blades, and 
is used for planing ends of stanchions absolutely square 
and true with the central axis, and also for turning ends 
of built girders and rolled beams to a neat finish. 

Next is a vertical punching, shearing, and angle - 
cropping machine, gear-driven by a 7 -h.p. motor, 
fixed on top of machine, extreme capacity, punching 
1 -in. holes through 1 in. thick, shearing f-in. plates, 
cropping angles up to 6 in. by 3 in. or 4 in. by 4 in. 



NOTES 



xli 



Next is a plate-edge planing machine, taking plates 
Up to 30 ft. long . 




Next is another vertical punching and shearing 
machine, without angle cropper, belt-driven by 6-h.p. 
motor in pit, capacity as previous. 



xlii 



NOTES 



Next we have a cold sawing machine, belt -driven 
by 6-h.p. motor. This machine is capable of cutting 




angles, tees, joists, and channels square or on bevel, 
the latter by means of a rotating head. 

Turning round into the second workshop bay, 280 ft. 
long by 31 ft. wide, the first machine is an angle 



NOTES xliii 

and tee cropping machine, belt-driven by a 6-h.p. 
motor. This machine, by simple adjustments, can 
also crop angles and tees on the bevel. 

The next machine is a powerful hydraulic machine 
tor rutting" joists up to 18 in. by 7 in. and channels 
up to 15 in. Two pressures may be used as re- 
quired, single equivalent to 90 tons, double equivalent 
to 275 tons. 

Next arc two horizontal punching, bending, and 
straightening machines, gear -driven from motors. 

The two hydraulic riveting machines are of the 
usual " Bear " type, and exert a pressure of 32 tons 
on the rivet when clenching. 

There are rive electric travelling cranes in the various 
bays, from 2^ to 16 tons capacity. 

In the smithy are the usual smiths' hearth and 
furnaces, lathe, saw, grinder, emery-wheels, and other 
small machines, also an hydraulic press for forging. 

The template shop is of ample size and well lighted. 
Roof-work and all other complicated items, such as 
theatre balconies, are laid down full size on the floor 
and the necessary templates made from the lines. 

Two illustrations of the works are here reproduced. 

Works on Metropolitan Railway. 

By the courtesy of Mr. W. Willox, M.Inst.C.E., 
Chief Engineer of the Metropolitan Railway, the 
members of the Concrete Institute visited the Metro- 
politan Railway's new offices at Baker Street, and the 
reinforced concrete bridge at King's Cross Station, 
in course of construction, on Saturday, October 1 2,, 
19 1 2. The members assembled at the entrance of 
the Baker Street Station, London, W., at 3 p.m., and 
subsequently journeyed to King's Cross. 

The following is a description of the works : — 

Metropolitan Railway's New Offices. 

The Metropolitan Railway Company is erecting a 
large block of offices adjoining the new station at 
Baker Street, to supersede the crowded offices at West- 
bourne Terrace and to concentrate in one building 
those at present scattered about various parts of their 
system. 

b 



xliv XOTES 

The principal dimensions are as follows : The total 
length of the front elevation will be 140 ft., and the 
height, measured from the foundations to the roof, 
will be approximately 90 ft. The back portion of 
the structure will have two wings, measuring respec- 
tively ill ft. in length by 38 ft. in width, and 100 ft. 
by 43 ft. for the smaller wing, the latter being con- 
nected to the booking -hall of the new station by a 
foot-bridge 82 ft. in span, 10 ft. wide, and with 
a height of 15 ft. 

A retaining wall in reinforced concrete, and of a 
length of 152 ft., will run parallel to the front eleva- 
tion. The total length of the retaining wall, including 
the returns, will be 212 ft., the height being 24 ft. 

The walls of the building are to be entirely in rein- 
forced concrete, of a thickness of 6 in., and for the 
principal elevation the wall is to be faced with brick- 
work and faience. 

The building will comprise a lower basement, base- 
ment, booking -hall floor, ground floor, first, second, 
and third floors, and a flat roof. The superloads up 
to the first floor included are to be 150 lbs. per square 
foot, the second and third being 90 lbs. per square 
foot, and the roof 40 lbs. per square foot. The total 
superficial area of floors and roof in reinforced concrete 
will be approximately 65,000 sq. ft. 

The building is to be carried on concrete stanchions 
over the new platforms, the lowest floor being level 
with the booking -hall of the new station ; store and 
strong-rooms and the heating-chamber being at a 
lower level and alongside a set of rails, thus facilitating 
the handling of the coal for heating and the stores. 

The ground floor, which is at street -level, accom- 
modates the suites of the principal offices ; and the 
board -room, which is planned between two committee - 
rooms, and with sliding doors, can be enlarged to hold 
the meetings of the company. 

These rooms will be panelled in hard wood, with 
double partitions and windows to shut out any noise 
from the railway below. 

The engineer's office is placed in the north wing, so 
as to get the necessary light for the drawing -office. 

Automatic lifts are provided in the staircase halls, 
the south one descending to platform -level to facili- 



NOTES \lv 

talc the collection and dispatch of cash, tickets, etc., 
the north one connecting the accountant's and other 
departments with the strong-rooms in the basement. 
< >n the top floor are kitchens, dining-rooms, and care- 
taker's quarters. 

The building will be heated throughout on the low- 
sure hot -water system. 

The whole of the work is under the control of Mr. 
W. W'illox. M.Inst.C.E., Chief Engineer of Metro- 
politan Railway. 

The architectural work has been designed by Mr. 
Willox's architectural assistant, Mr. C. W. Clark, 
A.K.I.B.A.. P.A.S.I. ; and Mr. O. G. C. Drury, 
A..M.I.C.E., is the resident engineer. The reinforced 
concrete work is on the Coignet system . 

Reinforced Concrete Bridge at King's Cross Station. 

The new bridge has recently been completed at 
King's Cross Station to connect Gray's Inn Road to 
1'entonville Road, through the site of the old booking- 
office. The whole of this work has been carried out 
under the superintendence of Mr. W. Willox, M.Inst. 
C.E., engineer of the Metropolitan Railway Company. 

The bridge, which is built in reinforced concrete 
on the Coignet system, is claimed to be the largest 
road bridge of this description in London. The 
various dimensions of the works are as follows : 
There are two spans composed of straight beams, 
the bridge being slightly on the skew. The main 
■-pan is 52 ft. and the smaller span 32 ft., giving a 
total length, taking into account the short end spans, 
•>f 130 ft. The width of the bridge, including the 
footpaths, is 60 ft. 

One of the main features of this work is that it had 
to be constructed without interfering with the traffic 
of the railway below ; and in order to support the 
wooden centering and moulds for the reinforced con- 

te work over the permanent ways, it was found 
advisable to utilise old steel trelliswork girders, which 
had previously been in use to support the floor of the 
booking-hall of the old station. 

The roadway, which has been calculated for a 
uniformly distributed load of 2 cwt. per square foot, 



xlvi NOTES 

and also for two moving point loads of 8 tons, situated 
at 6-ft. centres, has been designed in such a manner 
as to accommodate two lines of double -deck electric 
tramways of the usual London County Council type. 
Accommodation has been provided between the rein- 
forced concrete beams for the special cast-iron yokes 
and ducks for the supporting of the rails and the 
transmission of the electric power. 

The details of the reinforcement are in accordance 
with the Coignet system for the construction of straight 
beams. The main bars vary in diameter between 
^ in. and ij in., and are of mild steel with a round 
section. The tension and compression reinforcing bars 
are connected together by means of stirrups, also 
made with round bars of small diameter. These 
vertical stirrups are arranged in such a manner as to 
take up the shearing stresses, and also in order to form 
a mechanical connection between the main reinforce- 
ment of the beams. The slabs are composed of bars 
varying between g in. and § in. in diameter and 
arranged to form a meshwork. 

The work has been carried out by Messrs. W. King 
and Son, contractors, of London, licensees of the 
Coignet system. 



THE CONCRETE 
INSTITUTE 

AN INSTITUTION FOR STRUCTURAL ENGINEERS, 
ARCHITECTS, ETC. 



(FOUNDED 1908. INCORPORATED 1909) 



TRANSACTIONS 

AND 

NOTES 



VOLUME IV : PART IV 

COPYRIGHT 



Published May, 1913 

at the Offices of 

THE CONCRETE INSTITUTE, 

Demson House, 296 Vauxhall Bridge Road, Westminster. 

a 



OBJECTS OF THE INSTITUTE. 

The objects of the Institute are : — 

(a) To advance the knowledge of concrete and 
reinforced concrete, and other materials employed in 
structural engineering, and to direct attention to 
the uses to which these materials can be best applied. 

(b) To afford the means of communication 
between persons engaged in the design, supervision 
and execution of structural engineering works (ex- 
cluding all questions connected with wages and trade 
regulation). 

(c) To arrange periodical meetings for the pur- 
pose of discussing practical and scientific questions 
bearing upon the application and use of concrete 
and reinforced concrete and other materials employed 
in structural engineering. 



The Institute is not responsible for the views of individual authors 

as expressed in Papers, Letters or Notes, but only for such 

observations as are formally issued on behalf of the Council. 



COUNCIL. 



President : 

E. P. Wt-LLS. J.P. 

Past President : 
sry Tanner. CB..I.S.0 F.R.I.B A.,F.S.I.,etc. (Principal Archt.H.M. Office of Works). 

Vice-Presidents : 

H. Pbrci M.Inst.C.E., Chairman of Council, R.San. I., etc. : 

S. Meik, M.InstCE., M.I.Mech.E.; 

Edwin 0. Sachs?, F.R S Ed M A.Inst.Mech.E, Chairman of Executive B.F.P.G, etc. ; 

K. E Wkntworth-Sheilds, M.InstCE. (Dock Engineer. L. & S. W. Railway) 

Prof, Henri Adams, M.InstCE., M.I.Mech.E., F.S.I., M.S.A., &c. ; 



H. H. d. Anderson ; 

H. K. g. Bauber, F.C - 

D. B. Butler, Assoc.M.Inst.CE., F.C.S.. PP.sk.: 

A. C. Davis, Assoc.Inst.CE., F.C.S. ; 

5, E. de Vesian M.Inst.C.E. ; 

Alexander Drew. M.I.Mech.E.: 

E. FlANDER Etchells, F.Phys.Soc., A. M.I.Mech.E. : 

I. Ernest France, a rib a, M.R.San.I. ; 

Matt Gakbitt. AssocM.InstCE., F.R.I.B.A. ; 

R. Napier Harvey, Major RE. ; 

O^bonn C. Hills, F.R.I.B.A. (District Surveyor for the Strand) ; 

WILLIAM G Kirkaldv, Assoc. M.Inst.C.E. ; 

CHARLES F. Marsh. M.Inst.C.E.. M.I.Mech.E.. M.Am.Soc.C.E. 

J, MUNRO : 

W. G. Perkins (District Surveyor for Holborn) ; 

F. PCRTON, F.S.E. : 

A. Alban H. Scott, M.S. a. ; 

H. D. Searles-Wood, F.R.I.B.A., M.R.San.I. ; 

Licten Serraillier. ; 

T. B. Shore : 

Henry Tanner. F.R.I.B.A.; 

H. J. TINC.LE, M.InstCE. : 

R. W. VaWDRET, B.A.. AssocM.InstCE. ; 

G. C. WORKMAN, M.S.E. 



Bankers : 

PARR'S BANK. LTD. 

Charing Cross, London, W.C. 

Offices : 
Denison House, 
.' < VauxhaU Br ; dge Road, Westminster. 



S» relary. H. Kempton Dyson. 



FINANCE AND GENERAL PURPOSES 
COMMITTEE. 

Mr. H D. Searles-Wood, F.R.I. B.A., Chairman. 

Mr. Edwin O. Sachs. F.R.S.Ed. Mr. G. C. Workman. M.S.E. 

Sir Henry Tanner, C.B., I.S.O., F.R.I. B.A.. F.S.I. 

Ex-officio: President and Chairmen of Standing Committees. 

STANDING COMMITTEES . 

SCIENCE STANDING COMMITTEE : 
Prof. Henry Adams, M.Inst.C.E.. Chairman. 
Mr. E. Fiander Etchells, F.Phys.Soc, Vice-chairman. 
Mr. H. K. G. Bamber, F.C.S. Mr. Chas. F. Marsh, M.Inst.C.E . M.Am.Soc C.E. 

Mr. William Dunn, F.RJB.A. Mr. H. D. Searles-Wood, F.R.I.B.A. 

Mr. J. Ernest Franck, A.R.I. B.A. Mr. F. E. Wentworth-Sheilds. M.Inst.C.E. 

Mr. William G. Kirkaldy, Assoc. M.Inst.C.E. Mr. M. E. Yeatman. MA. M.Inst.C.E., 

M.Am.Soc.C.E. 
Mr. R. W. Yawdrey, B A.. Assoc. M.Inst.C.E., Hon. Secretary. 

PARLIAMENTARY STANDING COMMITTEE : 
Mr. H. Percy Boulnois, M.Inst.C.E., Chairman. 
Mr. W. H. Johnson. BSc, Vice-Chairman. 
Mr. H. H. D. Anderson. Mr. T. de Courcy Meade, M.Inst.C.E 

Mr. J. S. E. de Yesian, M.Inst.C E. Mr. W. G. Perkins. 

Mr. Matt Garbutt, Assoc.M.Inst.C.E.. Mr. Edwin O. Sachs. F.R.S.Ed.. etc 

F.R.I.B.A. Mr. L. Serraillier. 

Mr. Osborn C. Hills, F.R.I.B.A. Mr. Henry Tanner. F.R.I.B.A. 

Mr. J. Ernest Franck, A.R.I. B.A., Hon. Secretary. 

REINFORCED CONCRETE PRACTICE STANDING COMMITTEE 

Mr. Alexander Drew, M.I.Mech.E.. Chairman. 
Mr. Ewart S. Andrews, B.Sc. (Lond.). Mr. F. Purton, F.S.E. 

Mr. F. Bradford. Mr. L. H. Rugg. Assoc.M.Inst C E 

Mr. S. Bylander. Mr. T. B. Shore. 

Mr. Oscar Faber, B.Sc (Lond.). Mr. R. T. Surtees. 

Mr. Moritz Kahn. Mr. T. A. Watson. Assoc.M.Inst.C.E. 

Mr. P. W. Leslie. 

Mr. G. C. Workman. M.S.E., Hon. Secretary. 

TESTS STANDING COMMITTEE: 
Mr. William G. Kirkaldy, Assoc.M.Inst C.E.. Chairman. 
Mr. Alexander Drew, M.I.Mech.E., Vice-Chairman. 
Mr. H. K. G. Bamber, F.C.S. Mr. P. M. Eraser. A.R.I. B.A. 

Mr. D. B. Butler, Assoc.M.Inst.C.E. Major R. Xapier Harvey, R.E. 

Mr. A. C. Davis. Assoc.Inst.C.E., F.C.S. Mr. William F. King. 

Mr. Edward Dru Drury. F.R.I.B.A. Mr. R. H. Harry Stanger. Assoc.M.In-,t.C.E 

Mr. A. Alban H. Scott, M.S.A., Hen. Secretary. 



CONTENTS 



»S— PAGE 

Membership ... ... ... ... ... ... ... ... liii 

Accessions to the Library ... ... ... ... ... ... Hii 

Reinforced Concrete in Southern Nigeria 397 

By H. C. Huggins, M.Soc.E., M.C.I. , District Engineer F.W.I)., 
S. Nigeria, W. Africa. 

Twenty-seventh Ordinary General Meeting, November 14, 1912 ... 403 
Presidential Address ... ... ... ... ... ... ... 406 

Twenty-eighth Ordinary General Meeting, November 28, 1912 ... 435 
Paper by Mr. J. M. Theobald, entitled " Bills of Quantities for 
Reinforced Concrete " 435 

Twenty-ninth Ordinary General Meeting, December 12, 1912 ... 479 

Continued Discussion on Mr. Theobald's Paper... ... ... 480 

Paper by Mr. Gadd entitled, " Action of Acids, Oils and Fats 

upon Concrete " ... ... ... ... ... ... ... 503 

Thirtieth Ordinary General Meeting, January 9, 1913... ... ... 531 

Paper by Mr. W. Valentine Ball, Barri>ter-at-Law, entitled 
" Concrete in its Legal Aspect " -,^,2 

Discussion at Meeting- : Participation therein by — 

Alford, Mr. J. S 

Ball, Mr. Valentine 

Bare, T. E 

Boulnois, Mr. H. Percy, M.Inst.C.E 

Butler, Mr. D. 15., Assoc.M.Inst.C.E., F.C.S. .. 

Bylander, Mr. S„ M.C.I 

Corderoy, George 





572 


578 




565 


567 

424 


••• 5*5 


518 


5*5 
462 

470 



Cr - A. G.. F.S.I 

Cubitt, Mr. Horace. A.K.I. B. A 

Davis. W. E 

Etchells, Mr. E. Fiander, F.Pbys.Soc, A.M.I.Mech.E. 

428, 551, 557. 5 6 ii 5 6 2. 5 6 3. 5°4. 5 () 5- 
Fraser, Mr. Percival M., A.K.I.B.A., M.C.I. 

4U2. 519, 520, 527, 
Gadd. Mr. W. Lawrence. F.I.C.. M.C.I. 

514. 520, 523. 524. 525. 526. 527, 

Hill. Mr. Osbom C, F.R.I.B.A 

Hingston, Mr. Frederic. M. Quantity Surveyors' Assn. 

Hood, W. R., F.S.I 

Kahn. Mr. Moritz, M.C.I 

Kearns, K. M., F.S.I 

Lascelles, Mr. W. H., M.C.I 

Meik, Mr. C. S.. M.Ist.C.E. 

Member, AnjHon 457. 

Perkins, Mr. W. G 465, 521, 527, 528. 555, 564. 

Remnant. Mr. A. C, F.S.I 

Rogers, Major H. S., R.E., Surveyor of Prisons, M.C.I. 

Scott. Mr. A. Alban H.. M.S. A 451, 459, 518, 

Shepherd, Mr. Herbert, A.R.I. B. A., M.C.I 

Theobald, Mr. John M., F.S.I., M.C.I. ... 
Vawdry, Mr. R. W., B.A., Assoc.M.Inst.C.E. 

484. 514. 519. 

Watson, Mr. T. A.. M.C.I 

Wells, E. P., J. P. 434. 435. 448. 451, 474, 479. 4S0. 495, 

523, 531, 550, 561, 562, 563, 565. 572. 
Workman, Mr. G. C, M.S. E 488,498, 



57o. 571 

569. 
528, 

528, 



4 6 -- 
570. 



• 435, 



503. 

573 
52 1 . 



459. 462 

573- 574 
... 468 

57 J - 578 
529, 570 

529. 53o 

562, 563 
487,52] 

472 
490 
466 
569 
427 
465, 567 
572. 574 
.. 500 
... 562 
575- 570 
... 563 
496, 498 

525- 52b- 

45 7 ■ 45" 
5'4- 5l8, 

574- 575 
520, 530 



4."' 



NOTES 

MEMBERSHIP. 

On April 30, 1913, the Institute had 927 Members, 
Students, and 6 Special Subscribers. 

ACCESSIONS TO THE LIBRARY. 

DONATIONS. 

Receni Publications Presented by the Authors 
and Publishers. 

Presented by the Author, Mr. H. St. G. Robinson. 

Pamphlet entitled " Experiments on Adhesion of 
Old and New Concrete." 

Presented by the Author, Professor Ira fi. Woolson. 

6 pamphlets : — 

1 1 1 Report of Tests upon Sand-Lime Brick. 
{2) Two pamphlets entitled " Report of a Fire, 
Load, and Water Test." 

(3) Two pamphlets entitled "Report of a Fire 

and Water Test." 

(4) One pamphlet on Investigation of the 

Thermal Conductivity of Concrete, etc. 

Presented by the Author, Mr. H. J. Harding. 

One pamphlet entitled " Weight v. Measure." 

Presented by the Publishers, Messrs. Constable & Co. 

*' Reinforced Concrete Bridges," by Mr. Frederick 
Rings. 
Presented by the National Association of Cement 
Users . 
Pinal Report on Measuring Concrete." 

liii 



liv 



NOTES 



Presented by the Association Internationale Perma- 
nente des Congres de Navigation. 



" Rivers, Canals, 
Notes." 



and Ports : Bibliographic 



Presented by the Deutschen Beton-V 'ere ins . 

Bericht iiber die XIV Haupt-Versammlung am 13, 
1 4, and 1 5 Februar, 1 9 1 1 . 

The following Journals are also sent gratuitously by 
the various Institutions and Publishers: — 

The Architect." 

The Architect and Engineer of California." 

The Builder." 

Concrete and Constructional Engineering." 

Concrete-Cement Age." 

Engineering." 

Engineering News." 

Engineering Record." 

Ferro -Concrete ." 

Gas Engineers' Magazine and Gas Industries." 

The Indented Bar Bulletin." 

Machinery." 

Page's Weekly." 

Southern Builder and Engineer." 

The Surveyor." 

Tonindustrie-Zeitung." 

Proceedings and Journals of the following Societies : — 

City and Guilds of London Institute. 
Engineering Society, University College, Cork. 
Institute of Metals. 
Institution of Mechanical Engineers. 

„ ., Municipal and County Engineers. 

„ „ Municipal Engineers. 

Permanent International Association of Road Con- 
gresses. 
Royal Institute of British Architects. 
Society of Architects. 
Society of Engineers. 
Surveyors' Institution. 



THE CONCRETE INSTITUTE 



TWENTIETH ORDINARY GENERAL MEETING 

Thursday, November 9, 19 1 1 

THE TWENTIETH ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296, Yauxhall 
Bridge Road, Westminster, S.W., on Thursday, 
November 9, 191 1, at 8 p.m., 

Sir HENRY TANNER, C.B., I.S.O., F.R.I.B.A., 
F.S.I., etc., the President, in the Chair. 

THE CHAIRMAN (Sir Henry Tanner) :— There 
are several candidates for election. The Secretary will 
read their names. 

THE SECRETARY (Mr. H. Kempton Dyson ) 
read the following list of names, all of whom were 
declared duly elected : — 

Mr. Arthur Wm. Bungard, M.R.San. Inst., 
M.R.Soc.Arts, Licentiate R.I.B.A., Clerk of Works, 
H.M. Office of Works, London, S.E. 

Mr. William Henry Walker, Architect and Sur- 
veyor, Birmingham. 

Mr. JOSEPH S. McAven, Civil Engineer, Auckland. 

Mr. W. T. Oldrieve, F.R.I.B.A., F.S.I., 
F.S.A.(Scot. >, Principal Architect, H.M. Office of 
Works, Scotland. 

Mr. B. O. REYNOLDS, Instructor of Civil En- 
gineering, College of Engineering, Madras. 

Mr. S. G. ROBINSON, M.I.Mech.E., London. 

Mr. J. Osborne Smith, F.R.I.B.A., F.R.San. I., 
London. 



2 THE CONCRETE INSTITUTE 

Mr. Richard S. Thompson, Assistant Engineer, 
Otago Harbour Board, New Zealand. 

Mr. K. YOSHIDA, Engineer on the ■ Imperial 
Japanese Railways. 

Mr. William Bell, Chief Assistant to Messrs. 
D. & C. Stevenson, Civil Engineers, of Edinburgh. 

Mr. Henry Thomas Bromley, A.R.I.B.A., 
M. Inc. Assoc, of District Surveyors, District Surveyor 
for Wandsworth (East > . 

Mr. E. Patey Camp, Clerk of Works, M. Junior 
Inst, of Engineers, London. 

Mr. Paxdit Hira Lal, Assistant Engineer, Bili- 
mora Railways, India. 

Mr. L. H. Packer, Engineer, Gravesend. 

Mr. Harold F. PENTY, Architect and Construc- 
tional Specialist, London. 

It was also announced that the Council had admitted 
Mr. Walter Page Cooke, of London, E.C., as a 
Student. 

THE CHAIRMAN (Sir Henry Tanner i then 
delivered his Presidential Address as follows : — 

GENTLEMEN, — This Institute has now been in 
existence some three and a half years, and as this is 
the first Presidential Address that has been presented, 
it seems to be a fitting opportunity for taking stock 
of the work it has done during that period, and in so 
doing I may touch upon matters to which I have 
referred on other occasions. As some of you are 
aware, it came into being at a luncheon given by 
Mr. Edwin O. Sachs at the Ritz Hotel, in July, 1908, 
and the necessary regulations which had been prepared 
by Mr. Sachs were agreed to and Lord Plymouth was 
elected first President. Mr. Sachs is to be congratu- 
lated in so effectively organising a new Society. Under 
the regulations referred to the Council felt that they 
had very little power over the proceedings of the 
Institute, that power really resting with the Executive. 
This feeling became so strong that eventually the 
reconstruction of the Institute on similar lines to those 
of other Institutions of a like character came about, 
and these have worked satisfactorily, but are still open 
to improvement. However, at the time of the change 
the number of members was 881, which must be 



TWENTIETH MEETING, November 9, 1911 3 

considered as quite good, and is now about 875, while 
during the eighteen months ending last June the net 
gain had been 2T. Of course, in the case of a new 
iety the numbers joining would naturally be large 
at the commencement, but still, I should look 
for a larger net accession than 16 in the third 
year ; but we now seem to be slightly on the down 
grade, as the accessions have been rather less than the 
losses owing to deaths, resignations, and removals, 
some names having had to be struck off the rolls from 
failure to remit their subscriptions. 

The membership is distributed approximately as 
follow- : 350 in London, 260 in the country, and 26:0 
abroad ; while the professions, etc., are represented 
by 582 engineers, 91 architects and surveyors, 31 
concrete specialists, 45 chemists and cement manu- 

turers, and 28 contractors. 

interest appears to be taken in the papers read 
and discussions thereon than was formerly the case, 
while it becomes increasingly difficult to obtain papers 
which are at once suitable and of sufficient interest. 
It is desirable, therefore, that the causes which give 
rise to this state of things which has arisen should be 
inquired into and remedied. I am aware that this is 
not the only Institute which is forced to make similar 
admissions, but this is a young Institute and there 
should be abundant energy in it. We cannot afford to 
sit still and leave things to take any course, and which 
may be downward. 

These matters have been discussed by your Council, 
which at its last meeting appointed a Committee to 
consider and report how the Institute could best be 
broadened in its scope and interest and in its usefulness 
to members. 

Concrete and reinforced concrete form parts only of 
structures ; frequently there is much steelwork and 
other materials involved, including heavy timbering, 
either permanent or in false work. 

It is considered, therefore, that structural engineer- 
ing, being so intimately connected with our special 
subject, might well be regarded as coming within our 
purview, and that papers on such matters should be 
read and discussed. This is particularly the case 
having regard to the large number of engineer 

A2 



4 THE CON'CRETE INSTITUTE 

members. This can be done without in any way 
trenching on the prerogative of other societies, as 
there is no institute dealing particularly with such 
subjects. I hope that the results which this Committee 
may arrive at will be to the distinct advantage of the 
members. 

The Committee is empowered to take energetic steps 
to foster the structural engineering side, and thus we 
see how in future we shall in effect be not only a 
Concrete Institute but an Institution of Structural 
Engineers as well. With the extended field as in- 
dicated above, in which practically all our members 
are interested, and the majority actively engaged there- 
in, our work should be much more valuable and our 
membership influenced accordingly. 

In this connection, I cannot but think that member- 
ship requires better classification, and could usefully 
be rearranged on the lines of several of the engineer- 
ing societies, and the Committee might well consider 
the point. There might, for instance, be members, 
associate members, honorary members, associates, and 
students. In the future, also, it may be possible and 
advisable for us to hold an examination in advanced 
structural engineering, which shall in no way trench 
upon the examinations of other bodies, but be supple- 
mental thereto. Such prospects of extended scope for 
the energies of members is encouraging. 

Further, I think that much more use might be made 
of the Journal. Many members and others must be in 
possession of information which would be of the 
greatest value to their brethren, while short articles 
of approved quality and matter would, I believe, be 
welcomed by the Council. The Journal should be 
issued regularly at intervals not exceeding three 
months. 

Next, I wish to draw attention to the small attendance 
at the meetings. We can hardly hope that gentlemen 
will come forward to read papers, to open discussion, 
etc ., unless they can rely on an audience of a reasonable 
number of people, and, with one or two exceptions, at 
the meetings this year the audiences were certainly not 
of that character. I trust that members will endeavour 
to show more appreciation of the proceedings and 
help to improve them. The smallness of the attend- 



TWENTIETH MEETING, November 9, 1911 5 

ance cannot be due to the situation of the present 
meeting -room ; it is slightly out of the way, per- 
haps, but is very convenient of access, while it is 
the best that could be done, having regard to our 
income. We shall probably manage to pay our 
way this year, and perhaps maintain our deposit 

ount at its present level, notwithstanding that we 
have incurred considerable expense in removing and 
furnishing the new offices, which are found suitable 
and ample for our needs. What the balance may 
be, however, depends to some extent upon the pay- 
ment of subscriptions in arrear. 

The Annual Dinner was a success. We obtained 
the numbers expected, and I was supported by the 
['residents of the Institute of Civil Engineers, the 
Royal Sanitary Institute, the Surveyors' Institution ; 
also Sir Alexander R. Stenning, a past President of 
that body, Mr. Edwin T. Hall, Vice-President of the 
R.I.B.A., the Mayors of Hampstead and Holborn, both 
well-known architects, Mr. John Murray, the Crown 
Surveyor, the Chairman of a Sectional Committee 
of and the Secretary of the Engineering Standards 
Committee, Mr. A. White, Deputy Chairman of the 
Associated Cement Companies, and many others — 
recognition of our Institute which will be regarded 
with satisfaction. Apart from this, the attendances 
at the Summer Meeting were not altogether successful. 

Unfortunately, our income is small, and does not 
enable us to do many things which we could wish 
to have done for the information of our members. I 
hope that this will be borne in mind, and the better 
classification to which I have referred may afford the 
means to some extent for removing this disability. 

I am pleased to be able to say that the Institution of 
Civil Engineers has taken up the subject of reinforced 
concrete through the Committee which it appointed 
some time ago, and to which my name was added 
in June of last year ; a considerable sum of money 
has been devoted to experiments which are in pro- 
cess of being carried out, and I hope for much 
advantage from what I may regard as the co-opera- 
tion of that Institute. There is no doubt that experi- 
ments are needed in this country with a view to 
obtaining a consistent and complete series based on 



6 THE COXCRETE INSTITUTE 

materials to be obtained here and mixed and tested 
under similar conditions. At the present time we have 
to rely on experiments in America, Germany, and 
France, with cement of varying character and local 
aggregate, and it would be of the greatest advan- 
tage if these could be repeated in some cases at in- 
tervals for some years, the improvements in strength 
being so great. Perhaps this want may be removed. 

For some time past the Joint Committee appointed 
by the Royal Institute of British Architects, upon 
which we are represented, have had under con- 
sideration the revision of its first Report, and the revised 
edition was published several months ago in a much 
more handy form than before and at the small price 
of is. As Chairman of the Committee I desire to 
thank the members of the sub -committees, upon whom 
the work really fell, for their labours so freely given ; 
while it is satisfactory to think that this Report so 
far as it goes is accepted generally as the basis of 
local regulations for governing buildings of this 
character. These regulations require to be framed 
in such a way that they can be amended in order to 
keep pace with the acquisition of fuller and more 
complete knowledge, which will, no doubt, come in 
due time. The importance of being able to do this 
is shown by it having been necessary for the London 
County Council to obtain an Act of Parliament 
in 'order to make such alterations and additions to 
its Building Act to admit of reinforced concrete being 
used in an adequate way, and so not prevent the 
development of a method of construction which has 
been proceeding in America and on the Continent at 
a pace considerably in advance of this country, and 
at a saving of much money, while under suitable 
conditions it is a far better method of construction 
to adopt for safety, as in the case of countries liable 
to seismic disturbances . 

However, with the approval by the Local Govern- 
ment Board of the London County Council bylaws, 
after submission to several societies, including our- 
selves, for observations, it may be expected that there 
will be a considerable extension in the use of rein- 
forced concrete in London, as also in other parts of 
the country, other cities having also taken steps to 



TWENTIETH MEETING, November 9, ton 7 

admit of such methods of construction being usedj and 
it may be hoped that the list may be much extended 
md what it was when the Local Government Board 
quoted Newquay as being the only place the building 
ilations of which specifically admitted of the use of 
reinforced concrete. Suitable bylaws to this effect 
remain to be added to the model code. 

The preparation of such Reports and the adoption 
of bylaws regulating the use of reinforced concrete 
must tend to standardisation in design, and this must 
prove all for good. We have fortunately been fairly 
free from any serious failures in reinforced concrete 
St ruction, but experiences in America and on the 
Continent show that there is need for watchfulness. 
Although most of the failures have been attributed 
to bad construction, and the ignorance or carelessness 
ontractors and their employees, cutting in design 
may have been a contributory cause. 

it is interesting to note that the American Joint 
Committee on Concrete, which some time ago, like 
our own Joint Committee, issued an interim or first 
Report, has now under consideration a further Report 
brought up to date. 

The Board of Education appointed a Committee 
to inquire into the question of economy in building, 
and as to whether buildings of a more temporary 
nature could not very well be brought into use. Rein- 
forced concrete came in for its share of the discussion, 
but the estimates of cost varied largely, from 33 per 
cent, less to 10 per cent, more than for ordinary 
building. No difference of locality will account for 
these variations. There can be no question of the greater 
durability of structures of these materials with a mini- 
mum expense for maintenance, less cost for heating, 
concrete being a good non-conductor, while the reduced 
cube must make for economy. It seemed to me that wit- 
nesses having a more intimate knowledge of the cost of 
such buildings might have been called, while it should 
be possible to standardise such buildings, and so effect 
considerable economies. A loan period of thirty years 
was referred to, while the usual loan period for schools 
of ordinary construction was stated to be fifty years. 
It is impossible to understand the difference in treat- 
ment. It is very little good encouraging specific 



8 THE CONCRETE INSTITUTE 

proposals for the use of novel materials or methods 
for public elementary schools when such differences 
of treatment prevail, and in effect penalising any new 
system of building, while local bylaws make no special 
provision proper to the use of reinforced concrete. In 
order, however, to remove this last difficulty, it was 
suggested in the report that legislation should be 
promoted to exempt school buildings the plans of 
which had been approved by the Board of Education 
from the operation of local building bylaws. It also 
recommended that the Building Regulations of the 
Board of Education should be revised with the same 
object of removing obstruction. 

The Council inaugurated a series of lectures of an 
elementary character, given by Mr. R. W. Vawdrey, 
during the spring, which were fairly well attended, 
but we can scarcely hope to effect much good in com- 
petition with the courses given at the London County 
Council Schools and under the auspices of the London 
and other Universities, which have the advantage of 
testing apparatus, &c, and are generally better 
equipped. This is a matter worthy of the con- 
sideration of the Council. 

The Standing Committees of the Institute have done 
good service ; the new notation appears likely to be 
adopted generally in English-speaking countries, and 
its adoption is now being considered in America with, 
I understand, reasonable hopes of success. This, I 
think, must be regarded as very satisfactory. We have 
already intimated that we shall be happy to co-operate 
with the American Joint Committee in endeavouring 
to arrive at some common notation for English- 
speaking countries, the basis being that it shall be 
mnemonic, the symbols coinciding with the initials of 
the chief words in the terminology of the subject. In 
America there are some slight differences from our 
terminology for the same parts of construction. We 
think in these instances it should be possible to come 
to some agreement with material benefit to all 
concerned. 

Our Committees have also submitted reports on the 
standardisation of drawings, and the testing of con- 
crete, reinforced concrete, and materials employed 
therein, both of which are to be discussed at meetings 



TWENTIETH MEETING, November 9, 191 1 9 

to be held early in the ensuing session, and I Tiope that 
the discussion will be full and as complete as possible. 
Useful papers have been read before the Institute 
during the past sessions, and among those of last 
session that read by Mr. R. W. Vawdrey on " The 
1 M-sociation of Competitive Designs and Tenders" is 
one of much interest to many. The methods adopted 
for obtaining tenders are various, but it is seldom that 
tenders including design are asked for in any other 
branch of building than that of reinforced concrete. 
It is true that as a rule the general scheme is laid out 
by architects, and the reinforced-concrete designer has 
only to deal with the sizes of beams and columns, thick- 
nesses of slabs, and their reinforcement, but even this 
involves a very large amount of work where repeated 
by a number of persons or firms ; and it has to be 
remembered that quantities have to be prepared by the 
specialist, one reason being because the drawings are 
so incomplete that it would be impossible for any one 
else to prepare them. In the circumstances the quan- 
tities must be to some extent conjectural — a most objec- 
tionable state of things. Such quantities should, of 
course, be prepared from completed drawings and by 
an ordinary surveyor, as in the case of other processes 
of building, if competition is to be fair and on equal 
terms. The responsibility for their accuracy, however, 
lies between the specialist and the contractor, but the 
tendency is for any deficiency to be saved in some way, 
as, of course, in the case of keen competition there can 
be no margin to provide for such contingencies. With 
the architect's plans to work on there seems to be little 
opening for much variation when the R.I.B.A. rules 
have to be applied ; nevertheless, there results very 
considerable divergence in the amount of the tenders 
submitted on such conditions, and this would seem to 
be due partly to the ordinary differences in builders' 
tenders and partly to the quantities of work to be done, 
of which there may be a dozen different sets. This 
plan avoids the selection of a specialist who is probably 
interested in some system and more or less indefinite 
patent, but it involves the employment of an expert to 
check the specialist, while the method affords open 
competition for the design and limited competition for 
the carrying out of the work. This seems to me to be 



io THE CONCRETE INSTITUTE 

the wrong way about. From an architect's and from 
a surveyor's point of view the method is not satis- 
factory, and it prevents consultation and co-operation 
between the architect and specialist, which, to my 
mind, is essential to a proper arrangement and to the 
efficiency of the building and the best disposition of 
materials. Competition for design and construction 
must involve the utmost economy, which may perhaps 
be carried to the verge of safety ; otherwise there is 
very little prospect of the work being obtained, with 
the result that the labour involved is almost certainly 
thrown away. Economy in first cost appeals to most 
people, but there are other points to be considered, 
such as efficiency and* the running of unnecessary risks, 
by which comparatively nothing is gained. The 
specialists, however, have the whole matter in their 
hands, and it is no use theorising while they submit 
their designs and tenders — or rather builders do so for 
them — on the mere chance of obtaining the work. It 
is almost impossible to make a satisfactory contract 
when there are no quantities attached thereto and few, 
if any, drawings, these being left to be approved 
afterwards, a course which no one would think for a 
moment of adopting in any other branch of building. 
The sooner the specialists agree among themselves as 
to how they are to overcome this grievance the better 
for them and every one else concerned. 

Competition in reinforced concrete work has now 
proceeded to inordinate lengths, and it would seem that 
we have obtained the chief advantage to be derived 
from competition in design and that steps should be 
taken to put some limit to it. To effect this designers 
must be placed more in the position of consultants and 
not so closely associated with contracting firms as has 
hitherto been the case, and must remain so unless the 
two things can be dissociated ; and the expert, instead 
of checking the specialist, should co-operate, putting 
the latter on a higher plane. The disappearance of 
patent royalties and licences will no doubt facilitate the 
change. 

Much is said about the architectural treatment of 
concrete and that that treatment should be appropriate 
to the material. This subject was dealt with by Pro- 
fessor Beresford Pite in a most interesting paper, and 



TWENTIETH MEETING, November 9, [911 u 

we hope that the discussion may be continued in a full 
meeting later on. The subject is a difficult one, and 
formed one of the items to be discussed at the Inter- 
national Congress of Architects ; but although there 
was some discussion, it was considered that the time 
u.i- not ripe tor any resolution to be moved. The 
great desire is to make the whole building of rein- 
inforced concrete, including the external walls, and 
develope some new method of architectural treat- 
ment. There are many opportunities for this, as in 
isolated structures where various methods of surface 
treatment may be adopted ; but in town streets it is 
doubtful whether anything but stone or brick front 
elevations will satisfy building -owners or ground land- 
lords. 1^ seems equally logical to apply a stone or 
brick front to a reinforced concrete structure as to 
an ordinarx steel framed and concrete one. However, 
perhaps the discussion which we hope for may pro- 
duce novel proposals. 

The question of " Fireproohng " was most effec- 
tively handled by Mr. Richard L. Humphrey at our 
meeting a fortnight ago and made most interesting by 
the various slides exhibited. This is a direction in 
which it might be possible to obtain much useful in- 
formation if members would be good enough to 
forward to the Secretary any experiences that they may 
have knowledge of. There were two points that were 
well brought out — the superiority of a reinforced con- 
crete screen wall over a brick one, from experiences 
at San Francisco, and the effectiveness of wired glass 
in preventing the spread of fire. 

1 now come to the future. The Institute has a 
strong Council and an energetic Secretary, who are 
anxious that the Institute should take its proper place 
in the scientific world, and the members look for 
information and general assistance. In the Press it has 
been stated that " the time has now arrived when the 
serious and long required technical and practical assist- 
ance to be expected of an Institution of this kind 
should be rendered to those who are entrusted either 
with the design or with the execution of works in 
concrete and reinforced concrete " ; and that " if the 
Institute in its next few years does sound scientific and 
practical work on the broadest lines ... its success 



12 THE CONCRETE INSTITUTE 

is assured, and that a very large amount of useful 
work is expected during the impending session, while 
papers are desired of greater technical interest than 
those presented during the past year," and a pro- 
gramme of papers is asked for. 

To some extent, as I have shown, the Council has 
devoted itself to meeting the wants expressed above, 
and is, I think, fully alive to the necessity of obtaining 
good papers, but the great difficulty is to obtain the 
offer of them. Every one should therefore use his 
influence in this direction. After all, institutions of 
this nature are established for mutual information, 
and it is the business of all members to assist in this 
object. Everything cannot be left to the Council, its 
Committees, and the Secretary. I therefore ask for the 
active co-operation of all the members. 

It may be thought that my remarks have a pessi- 
mistic tendency, but that is not intended, my desire 
being to urge all our members to take what part they 
can in the work of the Institute for the benefit of all. 
With the extension of our scope to include structural 
engineering in its broad aspect we shall have a wider 
outlook and a future of great usefulness, with a possi- 
bility of a considerable increase in membership. I 
therefore conclude with feelings of the most optimistic 
character. (Applause.) 

MR. EDWIN O. SACHS, F. R.S.Ed. (Vice-Presi- 
dent) : — Gentlemen, I have been asked to propose a 
vote of thanks for Sir Henry Tanner's Presidential 
Address, the first address of its kind given in the 
Institution, and I think the members can congratulate 
themselves on having had such an interesting address, 
for it covers a vast field in a most interesting manner, 
and contains a very large amount of useful informa- 
tion and a number of very useful hints. 

Sir Henry, at the close of his address, suggests that 
it might be regarded as being slightly pessimistic, but 
he emphasises the fact that he looks optimistically 
into the future. 

I personally am somewhat of an optimist, and 
though this little child, the Concrete Institute, is now 
going through its children's diseases of the measles 
and scarlet fever, and so on, I am sure when it has 
recovered from these youthful ailments it will grow 



TWENTIETH MEETING, November 9, 1911 [3 

up to be that strong and important and influential 
individual which many a man — to make the comparison 
i^ to-day who has survived a somewhat delicate 
childhood. 

Being an optimist, I like to dwell on Sir Henry 
Tanner's points which speak of the recent success of 
the Institute. Its greatest success during the last two 
is was, perhaps, its First Annual Dinner. That, at 
any rate, was really a great success for a young Institu- 
tion. It was well managed, it went well, the speeches 
were interesting, and altogether it was a success ; and 
as an Institute we must give our very best thanks to 
Sir Henry Tanner for having personally arranged the 
dinner. If that may be taken as an example of what 
can be done by individual effort, I am sure that, if a 
great deal of individual effort is placed into the work- 
ing of the Council, we shall have numerous successes 
of this description. 

We also ought to congratulate ourselves that Sir 
Henry Tanner has been elected on the Institution of 
Civil Engineers' Reinforced Concrete Committee. It 
is an honour to this young Concrete Institute to have 
so able a representative there, and it is a very great 
step to think that the Institution of Civil Engineers, 
who in the earlier days of reinforced concrete — say, in 
1908 — ignored the subject, in this year — 191 1 — not 
only has such a Committee at all, and the Concrete 
Institute's President serving on it, but that they are 
actually represented at our Dinner by their President. 
1 Applause.) 

We must also congratulate ourselves that this year 
we had representatives on the Joint Committee on Rein- 
forced Concrete organised by the Royal Institute of 
British Architecture ; and here again we have the 
pleasure of having as our President this year the 
Chairman of that Reinforced Concrete Committee 
which has done such very good work. 

Another point, I think, for congratulation was that 
we made a start with the elementary educational, lec- 
tures of Mr. Vawdrey. They were most able lectures, 
and deserved far more support ; and if similar experi- 
ments are repeated, I am sure they will find favour. 

The last point which I would like to mention in 
congratulatory vein is that the standard notation— 



i4 THE CONCRETE INSTITUTE 

rather an obtuse subject — to which we devoted a con- 
siderable amount of time, is pleasing our American 
friends, and that we are at least half-way to some 
understanding as to a notation that is mutual to this 
side of the Atlantic and the other. 

In the matter of membership and in certain other 
directions we have, perhaps, been marking time, but 
that does not matter very much as we were going rather 
fast in certain directions. It is very seldom that an 
Institute which is not two years old — as was the case 
when I ceased to actively conduct its affairs in 1909 
■ — should already be mentioned in an Act of Parlia- 
ment as an authority to be referred to on questions 
of regulations. We had already in 1909 secured a 
standard which was quite that of many an older insti- 
tution, and marking time is not necessarily an evil. 
There have been some administrative changes to make, 
and those administrative changes took time. "Nothing 
better, however, could be said than what Sir Henry 
Tanner said in the latter part of his address, that 
now the administrative changes have been completed 
we should get to work, and do still more and better 
service for the science of concrete construction in 
the future. I hope that advice will be followed. 

Personally, I would refrain from touching on the 
question of the inclusion of structural engineering 
among the subjects to be dealt with by the Institute. 
I have views on the matter, but they are not suitable 
for this meeting to-night, and the only thing I wish 
to emphasise is that, having devoted such considerable 
time to administrative changes, I hope that the coming, 
year of the Institute will be mainly devoted to con- 
structive and effective work, rather than to any further 
time-taking reorganisation of its constitution. 

I think we have to congratulate ourselves on having 
Sir Henry Tanner as President. We have also to 
thank him for his very able Presidential Address, and 
no better recognition can be given than by according 
him a very hearty vote of thanks, and wishing him a 
most successful year of office. (Applause.) 

Mr. ALEXANDER ROSS, M.Inst.C.E. (Vice- 
President) : — Mr. Chairman and Gentlemen, I rise 
with much pleasure to second the vote of thanks to 
our President, Sir Henry Tanner. Sir Henry has done 



TWENTIETH MEETING, November 9, [911 15 

reat deal for this Institute : ho has nursed it from 
the first and paid it every attention, never failed us, and 
1- always willing to do something for our good and 
advancement. 

I consider that the Institute has, as a matter of fact, 
made decided progress. It is comparatively new, and 
as the mover of this resolution has said, very few 
institutions at the same age stand so well before the 
public, and before the profession, as this one does. 
That being so, I think we must be very careful before 
we bring about any revolutionary changes. There is 
no doubt that changes may be right, and once it is 
derided that they are undoubtedly right, then changes 
ought to be made, but we ought to be very certain that 
ire on the right lines before we move. 

Sir Henry necessarily talked to-night rather in a 
minor key. The membership has not gone up so 
rapidl) as we all hoped it would. The meetings 
have not been so well attended as they might have 
been, but there is one great essential fact — the papers 
have all been very good. Those I heard I considered 
excellent. 

One thing I might suggest. It has always struck 
me that possibly the endeavour to listen to an ex- 
cellent paper, and discuss it, all in one night, is 
more than we ought to expect. I think probably it 
might be an improvement if we fixed the length of 
the meeting and carried on discussions as other 
societies do, night after night until the subject has 
been thoroughly exhausted. There are many advan- 
tages. It secures that the meeting may not become 
tedious, and every one knows exactly when it is to 
close, and then there is the other advantage, that 
there is a period of a week or more in which those who 
take an interest in the subject can look it up, and come 
next time prepared to give a thoroughly good account 
of themselves in discussing it. 

Gentlemen, I am not going to detain you. As has 
been said, no discussion should be allowed on a Pre- 
sidential Address. Nothing could be said on the 
address we have just listened to except in its favour 
and in its praise, and I have much pleasure in second- 
ing the motion for a hearty vote of thanks to Sir 
Henry Tanner. (Applause.) 



16 THE CONCRETE INSTITUTE 

Mr. SACHS : — I will put the motion to the meet- 
ing, and we will carry it with full acclamation. 

The motion was put and carried amid loud cheers. 

THE PRESIDENT (Sir Henry Tanner.) :— 
Gentlemen^ I am very much obliged to you for the vote 
of thanks you have so cordially passed to me. I fear 
my remarks have been rather short, but perhaps they 
have had some pith in them. At all events, I was very 
anxious that the whole of the members of the Institute 
should see where we were, and understand really 
where we are wanting improvement. It seems to me 
almost the only way we can get to them. We can 
circulate this information scarcely in any other way, 
and I hope what I have said may produce better 
meetings, which will be more satisfactory to those 
people who come here and give us lectures. 

I do not think I have anything to reply to in what 
has been said by Mr. Sachs or Mr. Ross, and therefore 
I will conclude. 

I should say the date of the next Ordinary Meeting 
will be December 14th, when Mr. C. C. Workman 
will give a paper on il Some Recent Works in Rein- 
forced Concrete." 

We have provided refreshments in the offices 
upstairs, and we shall be glad if everybody will adjourn 
there. 

The meeting then terminated. 



TWENTY-FIRST ORDINARY GENERAL 
MEETING 

Thursday, December 14, 191 1 

THE TWENTY-FIRST GENERAL MEETING of 
the CONCRETE INSTITUTE was held in the 
Lecture Hall at Denison House, 296, Vauxhall Bridge 
Road, London, SAW, on Thursday, December 14, 
191 1, at 8 p.m. 

Sir HENRY TANNER, C.B., F.R.I.B.A., etc. 

(President 1, in the Chair. 

The following were elected Members of the 
Institute : — 

Mr. Arthur E. EVANS, Designer in Reinforced 
Concrete. Westminster. 

Mr. Philip Lewis Hanson, Contractor and 
Builder, Southall, Middlesex. 

Mr. Septimus Charles Hanson, M. S.A. Assoc. 
Inst. San. Engineers, Architect and Structural En- 
gineer. PAY. Dept., Lagos, Southern Nigeria. 

Mr. William David Rees (Colonel, V.D.),M. Iron 
and Steel Institute, M. International Association for 
Testing Materials, Consulting Engineer and Contractor, 
Westminster, S.W. 

Mr. Hubert Covell Sands, F.S.I., Architect and 
Surveyor, Lee, S.E. 

THE CHAIRMAN:— I will now call on Mr. 
Workman, who represents Messrs. Edmond Coignet, 
Ltd., to read his paper. 

Mr. G. C. WORKMAN, M.S.E., M.C.I., read his 
paper as follows : — 

'- B 



i8 THE CONXRETE INSTITUTE 

SOME RECENT WORKS IN REINFORCED 
CONCRETE. 

So much has already been said concerning the subject 
of reinforced concrete that I think it is possible to 
assume that the general principles and advantages of 
this comparatively new material are now well known. 

The object of this paper is to describe a few of 
the numerous works recently executed in reinforced 
concrete, and to bring out some of the more interesting 
features of each particular case and to show how 
various difficulties have been overcome. 

Owing to modern requirements, there is a growing 
tendency for the various branches of engineering to 
become specialised in order to obtain, by a continual 
study of each subject, the maximum amount of economy 
and efficiency. 

It is for this reason that a certain number of 
engineers have become specialists in the designing 
of reinforced concrete, each one adopting the particular 
method of reinforcement which he thinks best suited 
for the purpose, and I may mention here that personally 
for the past ten years I have been identified exclusively 
with the " Coignet System," which was one of the 
first rational and scientific methods of reinforcing 
concrete. 

As there are now a certain number of different ways 
of reinforcing concrete, I shall first give you a short 
description of the methods employed in the various 
works which I am about to describe. 

Commencing with the beams, which are usually 
considered the most important part of a structure, 
round bars of mild steel are used, the diameter 
varying between \ in. and i| in. The steel frame- 
works are designed in such a manner as to form 
independent units which can be easily made on the 
site and placed on the centering when required. In 
some cases the tension bars for the lower portion 
of the beams are all straight with a corresponding 
parallel bar in the upper compressed portion of the 
beam ; a mechanical bond between the upper and 
lower bars is provided by means of stirrups made 
of round mild steel wire varying between f\ m - an d 
\ in. diameter. These stirrups have their ends bent 



TWENTY-FIRST MEETING, December 14, 1911 19 

over the top bar, and they are fastened by means 
of annealed wire to the main bars so that their position 
cannot be changed during the process of concreting. 
The spacing of stirrups is, of course, varied in 
accordance with the shearing stresses. 

Another method of preparing these steel frame- 
works consists in grouping together seven tension 
bars of comparatively small diameter ; six of these 
bars are bent upwards at an angle of forty-five 
degrees and hooked over a longitudinal top bar | in. 
diameter in such a manner as to form a kind of truss. 
Additional stirrups are also provided, as in the first 
method described, to counteract any extra shear. 

This last arrangement has the advantage of being 
more economical than the first one because the section 
of steel in tension is made to decrease gradually 
towards the points of support where the bending 
moments are less, the extra steel being used to resist 
shear or diagonal tension. 

In regard to shear I would point out that in the 
first method, comprising vertical stirrups and hori- 
zontal bars, the vertical shear is taken up by the main 
bars and the horizontal shear by the vertical stirrups, 
whereas in the last-mentioned alternative the vertical 
and horizontal shear, or, in other words, the diagonal 
tension, is counteracted by the bars bent at an angle 
of forty -five degrees. 

The longitudinal top bar is, of course, necessary 
for the preparation of each unit. This bar is very 
useful to suspend the framework in the centering, and 
as it is situated in the upper portion of the beam it 
increases the resistance to compression. The upper 
end of the stirrups and shear members is secured by 
means of hooks to the top bar. This precaution is in 
accordance with the new rules of the Joint Committee 
of the Royal Institute of British Architects, which 
state that in every case care should be taken to bend 
or otherwise secure the ends of the rods to prevent 
them from slipping in the concrete. 

The negative bending moments in beams are 
counteracted by joint bars of sufficient length. 

In many of the buildings the steel frames of the 
pillars are made horizontally and placed in position 
in the casings when required. These frames are 

1: 2 



20 



THE CONCRETE INSTITUTE 



composed of main bars bound together either by 
-K in or i in. wire, forming helicals or horizontal 
tYes with a pitch of about 6 in. The object 
of these ties is not so much for strength as to keep 




Fig. i. 

the vertical bars in their proper position during the 
concreting. 

Concerning the reinforcement of rectangular floor 
slabs, this is provided by simply placing principal 
bars of about f in. to f in. diameter in the smaller 
spans and £ in. distributing rods at right angles to 
the others, so as to form a mesh, the bars of which 
are bent up gradually over the beams in order to resist 
contraflexure . 

As previously mentioned, round bars have been used 
throughout because they have the advantage of being 





Fig. 2. 



easily procurable in the open market, and because 
this section produces the minimum amount of contact 
between the various bars forming the units. It is 
obvious that flat surfaces of contact between bars 



TWENTY-FIRST MEETING, December 14, [911 .21 

should as much as possible be avoided because rust 
is likely to develop in such places, and this defect may 
ultimately become a source of danger. Another reason 
for round bars being favoured is that they offer a 




Fig. 



better surface of adhesion than any other available 
section. 

Having briefly described the general principles of 
the reinforcement used in the buildings which I am 



MUM ■ 



■■■■ 






e~ r~ f 



r - s- 








TWENTY-FIRST MEETING, December 14, 191 1 23 

going to show you on the screen, it is my intention 
simply to deal with some of the interesting features 
in each case. 

Before proceeding with illustrations of actual work I 
will first put before you a few diagrams showing the 
two methods of making steel frames for beams which 
I have already described. 

Fig. 1 shows the stirrups gradually spaced along 
the beam in accordance with the shear. The section 
shows how the top bars are utilised to hold the units 
in position during the concreting by means of small 
pieces of wood placed under these bars and having 
their ends resting on the sides of the casing. 

These top bars have also the advantage of keeping 
the bars of the slabs up at the junction of slabs and 
beams to take the tension due to negative bending 
moments, and it is important that the bars of the 
slabs should be held up as otherwise they are liable to 
be trodden upon by the men during the concreting, 
with the result that as the bars are not in their proper 
position to take up the tension, longitudinal cracks 
might appear over the beams, the concrete alone being 
left to resist the counterflexure . 

Fig. 2 is a diagram of the alternative method 
of making steel frames or units for beams. The 
various bars forming the lower group are kept 
about T V in. to 5- in. apart by means of wire passing 
between the bars and binding them together. 

Beams made with these particular units are usually 
described as being of uniform strength owing to the 
fact that the section of steel in tension is calculated to 
correspond as exactly as possible to the requirements 
of the curve of bending moments. 

Fig. 3 is a perspective drawing of a beam, slab, and 
pillar, also showing a lintel and walls. 

One of the first large buildings with which I had 
to deal was the second tobacco warehouse, for the 
Bristol Docks (Figs. 4 to 7). This work was carried 
out under the Docks engineer, and the contractors were 
Messrs. W. Cowlin & Son, of Bristol. 

The general dimensions of the structure are : 200 ft. 
in length by 102 ft. in width and about 96 ft. in 
height, and there are altogether nine floors calculated 
for a superload of 1^ cwts. per square foot. 



26 



THE CONCRETE INSTITUTE 



This building is identical in appearance to the first 
tobacco warehouse, but the inside is in reinforced 
concrete instead of being in steelwork with concrete 
floors. 

Besides the advantages of fire resistance and 
economy which this building offers over the first one, 





II > *5;®* 1 m 


1 OH 






i 



Fig. 7. — Driving Pile, Bristol. 



the internal accommodation is larger on account of 
the walls being only about 14 in. in thickness 
throughout the height of the building, instead of the 
considerable thickness of brick walls required in the 
first building. These thin brick walls or panels were 
supported at each floor by lintels, and the building has 



TWENTY-FIRST MEETING, December 14, 1911 27 

been divided in two by a partition in reinforced 
concrete 6 in. thick. 

The various floors were arranged in such a manner 
as to minimise the risk of fire by cutting off any 




particular floor from the others. The level of the 
floors is slightly raised at all lift openings and doors, 
so that it would be possible to flood any particular 
floor with a couple of inches of water if required. 



28 THE CONCRETE INSTITUTE 

This warehouse has been erected on reinforced 
concrete piles varying in length between 40 and 
50 ft. Fig. 6 is a view of the site showing the piles 
maturing. 

650 piles were required for the foundations. 

The load coming on each of the internal pillars 
amounted to 300 tons, and it was necessary, in order 
to transmit this load on to the ground, to group six 
piles together, uniting the heads by means of a cap. 

Each pile was calculated to stand a safe load of 
56 tons, and the diameters of the piles varied between 
14 in. and 15 in. 

The piles were driven into the ground by means 
of a steam monkey weighing 2 tons. The particular 
pile shown in Fig. 7 took about three-quarters 
of an hour to drive to its final set at a depth of about 
45 ^. 

Fig. 8 is a photograph of one of several buildings 
erected at Rainham, Essex, for Messrs. J. C. & J. Field, 
Ltd., the architects being [Messrs. Scott & Fraser, and 
the contractors Messrs. William King & Son, of London. 
The site is situated on the riverside and it is extremely 
marshy, so that the buildings had to be constructed 
on spread foundations or rafts in reinforced concrete. 

It is noticeable that although this building contains 
very heavy machinery and tanks for the manufacture 
of soap, it has been possible to spread these loads 
on to the ground evenly at a rate of only about a 
quarter of a ton to half a ton per square foot. 

Reinforced concrete buildings, being monolithic and 
lighter than brick or masonry work, are very well 
adapted to cases where unequal settlement is likely 
to occur, especially when such buildings are erected 
upon a reinforced concrete raft. 

Fig. 9 shows a perspective drawing of extensive 
premises erected in the city for Messrs. J. Grossmith, 
Son & Co., perfumers. The architect was Mr. H. A. 
Saul and the contractors were Messrs. Peacock Bros., 
of Brixton, for the first portion of the building, and 
Messrs. Stuart's Granolithic Co., Ltd., of London, for 
the second portion, which is shown on the left-hand 
side of the illustration. 

The building has altogether eight floors, the interior 
and roof being entirely in reinforced concrete. An 



TWENTY-FIRST MEETING, December 14, 191 1 29 

interesting feature of the building is that the heavy- 
front and side lintels are supporting the whole of the 
brickwork above. 

A considerable amount of difficulty was experienced 
in the design of the roof, owing to the fact that one 
of the slopes is much longer than the others, producing 
unequal thrusts. 

All the steel units for the various beams and pillars 
were prepared at Brixton in the contractors' work- 
shops, and carted on to the site ready to be placed in 
position. 




Fig. 9. 



It was necessary to proceed in this manner owing to 
the lack of room on the actual site of the building. 

Fig. 10 is a photograph of the flooring, during 
construction, for the hostel for women students at 
the Birmingham University. 

The architects for the work were Messrs. Buckland 
& Farmer, of Birmingham, and the entire building was 
carried out by Messrs. Richard Fenwick, Ltd., con- 
tractors, also of Birmingham. 

The total area of flooring was approximately 13,000 
square feet. 



3° 



THE CONCRETE INSTITUTE 



These floors were tested with a load 50 per cent, 
in excess of the specified superload, and the deflection 
did not exceed a thousandth part of the span. 




■ 



£ 

M 



jH 



•^ 






^ 





1 would take the opportunity, while we have on the 
screen a photograph showing the process of concreting, 



TWENTY-FIRST MEETING, December 14, 191 1 31 

to mention that there seems to be a considerable 
difference of opinion between the various methods of 
stopping the concreting in floor slabs, in beams, and 
in pillars. Personally, I am of opinion that the best 
method of stopping the concrete of the floor slabs 
is to stop the work over the beams, also that the 
concreting of beams should be stopped over the points 
of support. 

Concerning the pillars, the footings should be made 
first and the body of the pillar carried up to the level 
of the soffit of the beams, the remaining portion being 
concreted at the same time as the beams. 

One of the most interesting buildings with which I 
have been associated is the new Western District Post 
Office, which was erected about two years ago under 
the supervision of the Office of Works, the contractors 
being Messrs. William King & Son, of London. 

This building, which is situated between Cavendish 
Square and Wimpole Street, comprises a block of 
200 ft. frontage and 160 ft. in depth, with basement, 
ground floor, first and second floors, and flat roof. 

Fig. 1 1 is a view taken from the ground floor level, 
which is the main sorting-office. 

Owing to the fact that only four large pillars were 
allowed in the centre of this floor space, the spans 
between these pillars and the outer walls varied between 
45 ft. and 39 ft., so that the pillars, which are marked 
A, support loads of over 200 tons each. 

One of the chief features of the building is that the 
ends of the principal beams carrying respectively the 
first floor, second floor, and roof are suspended bodily 
by means of strong steel stirrups to upper beams 6 ft. 
high, forming the internal walls surrounding the inner 
court above the various floor levels. By this means 
it was possible to obtain a maximum height for the 
windows, which was a condition stipulated by the Office 
of Works. This condition, however, brought about a 
question as to whether this method of suspension could 
be used without danger, the two beams having a 
span of 39 ft. and supporting the first floor with a 
superload of 1 cwt. per square foot, the upper 
supporting beam having a span of 45 ft. There was 
no evidence that this particular arrangement had ever 
been adopted before, at least for spans of such large 
dimension. 



32 



THE CONCRETE INSTITUTE 



I am glad to say that the problem was solved in a 
satisfactory manner, with the result that the two sus- 
pended beams 39 ft. long each, and the beams across 
the inner court supporting the skylight, appear to have 
been made in one single span of about 118 ft. 




Another noticeable feature is found in the extensive 
beams over 12 ft. in height, which carry the other end 
of the suspended beams. These 12 -ft. beams have 
a span of 45 ft., and it was necessary to provide in 



TWENTY-FIRST MEETING, December 14, 191 1 33 

the portion of these beams underneath the first floor 
a series of large windows situated below the neutral 
axis of the beam, which occurs approximately at the 
level of the first floor. 

The pillars marked A are 34 in. by 34 in. The 
height between the ground floor and first floor is 
18 ft. The two principal beams marked B are 14 in. 
by 60 in., with a span of 45 ft. They support two 
secondary beams marked C, the dimensions of which 
are 10 in. by 40 in. with a span of 37 ft., and these 
support other beams marked D. These beams are also 
suspended to the upper beam above the floor level, 
forming walls of the inner court, in the manner which 
I have already described, with the exception that these 
particular beams do not extend through the inner court. 

Fig. 1 2 is a view of the first floor, showing the 
extensive area of flooring without any pillars. 

The walls of the inner court marked E are the upper 
beams, 12 in. thick and 6 ft. high, with a span of 
45 ft., which are supporting the suspended beams 
which I have already mentioned. 

The two vertical projections shown on the beam E 
contain the steel stirrups by means of which the lower 
beams are suspended. 

The beams F have scantlings of 14 in. by 48 in. and 
a span of 45 ft. 

The two beams G, which apparently are resting on 
panels H, are in reality suspended to an upper beam 
similar to E. 

Fig. 1 2 is a photograph taken just before testing. 
This operation was carried out by means of sand 
gradually spread over the surface. 

Large areas of flooring were tested, the specification 
being one and a half times the superload, and the 
deflection not to be greater than ff( 7oth of the span. 
The deflection recorded in the beams did not, however, 
exceed rroofh t0 Wooth of the span, and no permanent 
deflection was noticed. 

I would take this opportunity to state that in my 
opinion it is essential to place underneath the beams 
which are to be tested a few strong emergency props 
not touching the soffit of the beam by about % in. 
This has the effect of reassuring the men who are 
carrying on the loading operation, and it also has the 




0- 
i 3 



TWENTY-FIRST MEETING, December 14, 191 1 35 

effect of preventing any sudden collapse which might 
be due to unforeseen circumstances. 

Fig. 13 is the front elevation of the Western 
District Post Office in Portland stone, executed by 
Messrs. Galbraith & Son. All the other walls were 
made in reinforced concrete 5 in. thick. The London 
County Council By-laws which are shortly to be revised 
will, I hope, encourage architects to study the question 




Fig. 13. — Western District Post Office. 

of reinforced concrete applied to the front elevation 
of buildings. 

Fig. 14 is a view of a large factory erected about 
eighteen months ago at Bailiffe Bridge, near Leeds, 
for Messrs. T. F. Firth & Sons, Ltd., carpet manufac- 
turers. The architects were Messrs. Walsh & Nicholas, 
of Halifax, and the contractors Messrs. Henry Atkinson 
& Sons, Ltd., of Leeds. 

c 2 



3 6 



THE CONCRETE INSTITUTE 



The main building is four storeys high and 176 ft. 
long, with a width at one end of 70 ft. and at the other 
end 'of i t i ft., the building being in the shape of 
an " L." The total floor area is approximately 52,000 
square feet. 




The factory is built on a very steep incline, and 
to overcome difficulties of levels on the site from the 
ground to first floor a retaining wall 16 ft. high was 
constructed in reinforced concrete. 



TWENTY-FIRST MEETING, December 14, 191 1 37 

The staircases throughout the building are also in 
this material. 

The work being situated in the very midst of the 
York stone district, local prejudice prevented treating 
the external walls as a distinctly concrete building. 
A compromise was effected by facing the main rein- 
forced concrete pillars and the lintels of the various 
floors with local self -dressed wall stones 5 in. on 
bed. The recessed wall spaces under the salt-glazed 
brick arches are finished with rough -cast. 

I am informed that this large factory does 
not exceed in price per super-yard of floor area a 
similar factory which was built twelve years ago in 
the same neighbourhood with steel girders and 
stanchions, wooden floors and stone walls. 

Fires are very frequent in this district, causing 
tremendous loss and inconvenience. The value of 
the carpets stored in this warehouse being very con- 
siderable, it was decided to adopt reinforced concrete 
for this building. 

In this particular instance a very large saving was 
effected in the yearly premiums owing to the low rate 
which the Insurance Companies are prepared to grant 
to buildings in reinforced concrete. 

Fig. 15 shows the interior of one of the floors with 
a central row of pillars, the span of the main beams 
being 35 ft. It will be noticed that the main beams 
have been arranged parallel to the windows in order 
to get the maximum amount of light for weaving 
purposes. 

The floors are calculated for a superload of i\ cwt. 
per square foot with a factor of safety of four. 

Fig. 16 is a view during the execution of the work 
showing the centering for the main beams. This affords 
a striking example of the advantage which there is in 
using unit reinforcement for the beams, because it 
enables the latter to be lifted bodily into the box 
moulds and suspended in the manner I have previously 
described, ready for concreting. 

You will notice one of the units of a 3 5 -ft. beam 
being placed in position by means of a crane. 

The existing buildings and the new reinforced con- 
crete workhouse are connected by means of two foot- 
bridges, having a span of 50 ft. each and a width of 
about 6 ft. (Fig. 17). 




Fig. 15. — Interior of Factory at Bailiffe Bridge. 




Fk;. 16. — Warehouse, Bailiffe Bridge, in course of construction. 



TWENTY-FIRST MEETING, December 14, 1911 39 

These foot-bridges are also made to support con- 
veyors . 

Although they have the appearance of an arch, they 
have in reality been calculated as straight beams in 
order to avoid any thrust on the walls. 




A very large amount of reinforced concrete work 
has been carried out during the last two years in 
Jamaica. 

Fig. 1 8 is a photograph of the new Government build- 



TWENTY-FIRST MEETING, December 14, 191 1 41 

ings erected at Kingston, Jamaica, for the Government. 
The architects were Messrs. Nicholson & Corlette, of 
London, and the contractors Messrs. William Cowlin & 
Son, of Bristol. 

This large building, which is entirely in reinforced 
concrete, contains the General Post Office and the 
Treasury. 

The dimensions of the Post Office building are 
121 ft. by 132 ft., and the Treasury 187 ft. by 88 ft. 

In preparing the design the architects had to con- 
sider the question of earthquakes, and consequently 
the foundations of these buildings have been con- 
structed in such a manner as to offer the least possible 
obstruction to shocks or movements of the ground. 
The foundation is practically in the form of an immense 
raft composed of strong slabs and beams, the latter 
uniting the various footings of the pillars. 

The superstructure is of the type usually adopted 
in hot climates with spacious verandahs and colon- 
nades . 

All the roofs are flat and covered with several inches 
of gravel. 

Fig. 19 is a view of the back elevation of the 
building. The scantlings of the pillars vary between 
24 in. and 18 in., and some of these are octagonal 
in shape. 

The average span of the beams supporting the roof 
is 20 ft. and the average thickness of the slabs is 
4 in. 

The superload on first and second floors is 150 lbs. 
per square foot, and the roof was calculated for 84 lbs. 
per square foot. 

The making of the steel frameworks and, in fact, 
all the labour was carried out by natives working under 
a few experienced supervisors. I am informed that 
most of the concreting was done by native women 
carrying the concrete in baskets. 

Fig. 20 is a view of the new King's House at 
Kingston, Jamaica. This contract was carried out 
simultaneously with the one previously described, 
under the same architects and by the same con- 
tractors. 

The foundations were also made by means of a 
raft, and, in fact, the same type of construction was 
adopted as for the public buildings. 



44 THE CONCRETE INSTITUTE 

A large swimming-bath was provided, and there are 
several remarkably fine dancing and reception halls. 

This building is intended as a residence for the 
Governor of Jamaica. It is composed of a ground 
floor, principal floor, top floor, and flat terrace roof, 
the latter covered with several inches of gravel. 

Needless to say, these buildings have been con- 
structed not only to resist earthquake shocks but also 
to resist fire, and you will, no doubt, remember that a 
very severe conflagration followed the earthquake which 
happened in Jamaica many years ago. It is for this 
reason that practically all the buildings of any import- 
ance in Jamaica are at present being constructed in 
reinforced concrete. 

Figs. 21 and 22 are the new Hollo way Money Order 
Department, which is the latest of a series of large 
buildings for the extension of post-office facilities in 
London, under the instructions of H.M. Office of Works. 
The work was executed by Messrs. William King 
& Son, of London. 

The entire construction, with the exception of the 
front wall elevation, is in reinforced concrete. 

The building is in the shape of an " E." The total 
length of the front measures approximately 292 ft. 
and the depth of the main body about 50 ft. 

The three wings measure respectively 88 ft. by 
42 ft., 1 01 ft. by 42 ft., and 76 ft. by 42 ft. 

The building is composed of a basement, five rein- 
forced concrete floors, and a flat roof in the same 
material. There are also a large number of inter- 
mediate floors in the main body, which are used for 
cloak-rooms. 

The total height of the structure from the ground 
level to the roof is approximately 85 ft., and all the 
stairs and balconies are in reinforced concrete. 

Fig. 23 is a view of the completed elevation in 
brickwork and masonry, which was carried out by 
a separate contract by Messrs. Leslie & Co., Ltd. 

Although the front elevation has been executed in 
masonry, the walls of the wings are in reinforced 
concrete of a thickness of 5 in. only. 

The building is fitted with ventilating shafts and 
foul-air ducts, also constructed in reinforced concrete. 

At the back of the building, and partly buried in the 



m$ 



ill 




4\,. 



MM 





Fig. 21. — Reinforced Concrete Elevation of Holloway Money Order Department. 







m 



V 



TWENTY-FIRST MEETING, December 14, 1911 47 

ground, there is a large boiler-house, the dimensions, 
of which are 47 ft. in length, 37 ft. in depth, and 26 ft. 
in height. It was necessary to construct heavy retain-, 
ing walls for this purpose owing to the fact that the 
whole of the ground is composed of clay, and, as is 
well known, this kind of ground is rather treacherous 
on account of the fact that it has a tendency to become 
very soft in wet weather. 

The underground passage in reinforced concrete 




Fig. 23. — Necessary Elevation of Hollow-ay Money Order Department. 

provides a means of communication between the various 
wings of the building and the boiler-house. 

A water reservoir, containing about 10,000 gallons, 
was also built, buried in the ground. 

A remarkable feature of this work is the consider- 
able rapidity with which it was executed. The con- 
creting operations began at the end of December, 1909, 
and the entire building was practically finished at the 
end of July, 1 9 1 o, so that, taking into account a month 
for preparing the excavations, concrete footings, etc., 



48 



THE CONCRETE INSTITUTE 



the reinforced concrete portion of this large building 
was erected in eight months, which, in my opinion, 
constitutes a record. 

Fig. 24 is a photograph of the interior of one of the 




wings, showing the central row of circular pillars. The 
superload on the various floors was only f cwt. per 
square foot, and the floors were tested by means of 
piling up bricks to a sufficient height to produce a 
superload of about ij cwt. per square foot. There was 



f 





.;-_.^.* — . .* . 



■ w<V*^ 




I f 

<m 

i 

1 
j 


I 




.;■: 


Li 




^H 






5 o THE CONCRETE INSTITUTE 

no permanent deflection, and the results of the tests 
were considered satisfactory. 

Whilst I am dealing with the question of super- 
loads I would like to mention that it has been my 
experience that architects and engineers are inclined 
to specify superloads which are obviously far more 
considerable than what is really necessary. This is 
probably due to the fact that in many cases reinforced 
concrete is a novelty to them, and by specifying a 
comparatively high superload they hope to guard 
themselves against failure of the work. It is well 
established, however, that any failures which have 
occurred have been due either to the premature removal 
of props and centering, or, in a few isolated cases, 
to faulty design, so that in reality nothing is gained 
in security by specifying a higher superload than is 
required. 

In the case of this building the Office of Works, 
who are thoroughly acquainted with the use of rein- 
forced concrete, have not hesitated to specify a super- 
load of f cwt. per square foot, which is quite ample 
for their requirements, and which has the advantage, 

of course, of being economical. 

All the works concerning which I have shown you 

illustrations and given you a description have been 

so far with respect to buildings. I will now show 

you some works of a different character. 

Fig. 25 is a photograph of a foot-bridge erected on 

the Thames bank at Erith for the Erith Oil Works, Ltd. 

The construction was carried out by Messrs. Friday & 

Ling, of Erith, under the supervision and from the 

general design of Messrs. Scott & Fraser, architects, 

of London. 

The total length of the work is approximately 150 ft. 

with a width of about 6 ft. 

Fig. 26 is another illustration of a foot-bridge at 

Higham-Hellesdon, erected by Messrs. D. G. Somer- 

ville & Co., under the supervision of Mr. A. E. Collins, 

the City Engineer of Norwich. 

The total length of the foot-bridge is approximately 

340 ft. with a width of 7 ft. It was built on fifty 

piles 13 ft. long each. 

Figs. 27 and 28 are views of a road -bridge erected 

at Mauld, near Inverness. 



TWENTY-FIRST MEETING, December 14, 1911 51 

The work was carried out by Messrs. McLaughlin & 
Harvey, Ltd., contractors, of London and Belfast, 
under the supervision of Messrs. Scott & Fraser, archi- 




tects, of London, who are responsible for the general 
design of the work. 

The total length of the bridge is 180 ft. with a width 

D2 




Fig. 28.— Pier at Mauld Bridge. 




Fig. 29.- -Bowstring Bridge at Barijoed 



TWENTY-FIRST MEETING, December 14, 1911 53 

of 12 ft. between parapets. Four of the spans measure 
35 ft., and the remaining span measures 45 ft. 

The river is liable to become very high and the 
current is very rapid at certain times of the year. 
It was found necessary to design the bridge in such 
a mariner as to protect the piers against the shock 
of floating timber, and also to resist the shocks of the 
floating blocks of ice during the winter months. 

The foundations of the piers were made by driving a 
certain number of reinforced concrete piles in the bed 
of the river, encasing these in a solid block of concrete. 

Fig. 29 is one of two bridges erected for the Powell 
Duffryn Steam Coal Co., Ltd., under the supervision 
of their engineer, Mr. J. M. Greenhow, the contractors 
for the work being Messrs. Watt Bros., of Cardiff. 

This bridge, which is of the bow-string type, is 
calculated to carry two lines of railway with locomotives 
weighing 50 tons and wagons 19 tons each. 

The bridge is built on the skew, the dimensions 
being 56 ft. 9 in. in span with a width of 26 ft. 8 in. 
and a height of bow-string beam of 13 ft. 3 in. 

The remarkable feature of this bridge is that it 
has been constructed underneath and on both sides 
of an existing steel bridge, which had become unsafe 
owing to corrosion produced by the fumes of sulphur 
and ammonia. The advantages of reinforced concrete 
in such cases are obvious. The reinforced concrete 
bridge was first allowed a sufficient time to harden 
and was then ready for service on the removal of 
the existing steel bridge, which operation was carried 
out in 48 hours. I had the opportunity of testing 
this bridge quite recently. The test was carried out 
by means of locomotives and loaded wagons, the 
maximum deflection under the bow-string beams being 
only about j 1 ,., in. without any permanent set. 

Fig. 30 is a view of an elevated tank, also for the 
same Mining Company, erected by Messrs. Watt Bros., 
of Cardiff. 

The general dimensions of the tank are 100 ft. 
long, 32 ft. wide, and 5 ft. 3 in. high. 

The remarkable feature of this tank is that although 
the inside was not rendered it is perfectly watertight. 
This is due to the fact that the aggregate was very 
carefully graded, and also on account of the height 
of the water being only 5 ft. 



54 



THE COXCRETE INSTITUTE 



Fig. 3 i is a photograph showing the underside of the 
large bunkers erected at Kinlochleven for the British 




Aluminium Co., Ltd. A very large amount of rein- 
forced concrete work was erected for this Company 
from the designs and under the superintendence of 



TWENTY-FIRST MEETING, December 14, 191 1 55 

Mr. A. Alban H. Scott, M.S.A., the contractors being 
Messrs. R. Mc Alpine & Sons, of Glasgow and London. 

The total capacity of this large bunker was over 
80,000 cubic feet. 

The main feature of this enormous work is the 
suspended hopper shown in the illustration, which has 




Fig. 31. — Underside of Bunkers, Kinlochleven. 

been calculated to carry a total load of about 2,0.00 tons 
in addition to its own dead load. 

This bunker is divided up into a certain number 
of transverse compartments torming large suspension 
beams, carrying the horizontal beams and inclined 
panels of the hoppers. In this manner the entire space 
underneath the bunkers is fres for conveyors and other 
machinery. 

Fig. 32 is a view of the West Pier, Newhaven, which 



TWENTY-FIRST MEETING, December 14, 191 1 57 

has been underpinned by means of about 700 
reinforced concrete piles. This work was carried out 
under the supervision of Mr. Charles Morgan, Engineer- 
in-Chief of the London, Brighton & South Coast Rail- 
way, the contractors being Messrs. W. Hill & Co., of 
London. 

It was found necessary to replace the old wooden 
piles supporting the concrete work on account of the 
decayed condition of the wood. 




Fig. 33. — Lifting Pile at Newhaven. 

The reinforced concrete piles, or more accurately 
sheet piles, were 16 in. by 16 in. in section, and some 
of the longest piles measure 52 ft. over all. They 
were driven by means of a steam monkey weighing 
2 tons. 

Some of the piles were driven a considerable dis- 
tance into the hard chalk, which is a proof of the 
strength of reinforced concrete piles. 

When visiting the works I had the opportunity of 



58 THE CONXRETE INSTITUTE 

seeing one of these piles, weighing over 6 tons and 
measuring 52 ft. in length, being lifted at one end 
by means of a crane, the other end resting upon a 
truck. The deflection in the middle appeared to be 
only about \ in. (Fig. 33). 

I am informed that some of the piles for the Bristol 
Tobacco Warehouse, which I have previously described, 
were elevated in a similar manner, producing a deflec- 
tion in the middle of over 1 in. without any apparent 
injury to the concrete. 

The obvious conclusion is, of course, that reinforced 
concrete piles possess, and, in fact, reinforced concrete 
in general possesses, a very considerable amount of 
elasticity. 

Fig. 34 is a view of a wharf recently constructed by 
[Messrs. D. G. Somerville & Co. for Messrs. J. E. 
Butt & Sons, at Portslade. 

The work is composed of piles and sheet piles con- 
nected by means of beams and supporting reinforced 
concrete panels held in position by means of tie beams 
and concrete anchor blocks. 

The main piles are 12 in. by 12 in. with a length 
of 25 ft. These piles were driven 15 ft. centres, the 
intervening space being made up with sheet piles 22 ft. 
long, having a sectional area of 6 in. by 18 in. 

The remarkable feature of this work is that the piles 
and sheet piles had to stand very heavy blows owing to 
an exceedingly hard stratum of ground through which 
they had to be driven. 

There are a certain number of other works recently 
erected with which I have been connected, which I 
should have had great pleasure in describing to you. 
I find, however, that this would require more time than 
I have at my disposal. 

I have endeavoured in the various examples of 
work which I have placed before you to illustrate all 
the various uses of reinforced concrete, namely, for 
floors, beams, pillars and walls, spread foundations, 
also foundations by means of piles, bridges, bunkers, 
water-tanks, and finally marine works. 

I will now conclude by saying that the object of 
this paper has been to show how certain practical 
difficulties may be solved in reinforced concrete con- 
struction, and it is my hope that some of the works 



60 THE CONCRETE INSTITUTE 

which I have put before you to-night will still further 
strengthen the confidence which English architects and 
engineers are showing in this comparatively new 
method of construction. 

DISCUSSION. 

Mr. F. E. WEXTWORTH-SHEILDS, M.Inst. C.E. : 
—Mr. Chairman and gentlemen, I have very great 
pleasure in proposing a most hearty vote of thanks to 
Mr. Workman for his very interesting paper. In fact, 
I have a feeling of gratification that I am, perhaps, 
in some slight measure responsible for this paper, as 
I used my best endeavours to persuade Mr. Workman 
to give this Institute a paper in which he should 
describe the large number of works with which he has 
been connected in this country, and I am sure we are 
all very grateful to him for having shown us, by means 
of these slides and by his lucid description, the varied 
work which has been done by his firm. Mr. Workman 
represents in England a man who is the son of a 
pioneer, if not the pioneer, of reinforced concrete. 
Those members of this Institute who had the pleasure 
of being shown over certain works in Paris last year 
will remember that M. Coignet showed us a reinforced 
concrete roof that was constructed near Paris by his 
father, M. Francois Coignet, some fifty-eight years 
ago ; and we recollect that he not only showed us this 
roof, but that he was good enough to have a hole cut 
into it so that we might see that the steel, which was 
put there more than half a century ago, was still in 
perfect condition. We were very much struck with the 
fact that although the science of reinforced concrete 
was then quite in its infancy, M. Coignet had seized 
the idea of the right disposal of steel in concrete, and 
had put his steel on the under side of his slab in order 
that it might take up the tensile stresses. In fact, that 
roof was a correctly designed reinforced concrete slab. 

Coming to modern times, and dealing with the 
various structures which Mr. Workman has described 
to us this evening, there are one or two questions I 
should like to ask him. With reference to the piles 
for the Bristol tobacco warehouse, which I imagine, 
from their circular form, were helically reinforced, I 
should like to know whether he used a helmet filled 
with sawdust or any softening material, or whether he 



TWENTY-FIRST MEETING, December 14, 191 1 61 

drove the piles with a wooden dolly or without any 
sort of pad, allowing the ram to fall directly on to the 
pile. As a matter of fact, I have seen a pile that was 
not helically reinforced driven without a helmet quite 
successfully, but the pile was protected in a measure 
by being surrounded with very strong clamps or straps, 
which acted, as it were, as a temporary helical rein- 
forcement to prevent the concrete bursting under the 
blow of the ram. 

I should also like Mr. Workman to give us, if it is 
not asking too much, a little detail of the design of 
that large column he showed us in the post-office 
building, which, he said, had to support a load of two 
hundred tons . It was a very large column, and it would 
be rather interesting to know whether, for instance, 
there were four rods in it or six rods in it, and how the 
steel was placed, and whether there were transverse 
stirrups or connections between the main rods, and if 
so, how they were placed. 

It would also be very interesting if he could give us 
some details of those suspended beams, which, I think, 
are perhaps rather a novelty— at all events, for a beam 
of that size. We should like to have some details of 
the suspension — how the links were attached to the 
main beam and to the beam below. 

One more question I should like to ask Mr. Work- 
man, and that is, after all his experience in buildings, 
what does he recommend for covering a reinforced 
concrete flat roof? That is a difficulty which many 
engineers have to struggle with. In France, I believe, 
the common plan is to cover the top of a flat roof 
with sand, or even with garden mould, but the English 
mind seems to shrink from growing geraniums on 
the top of a house, it prefers to have them down 
below. (Laughter.) I have only had personal ex- 
perience of one flat reinforced concrete roof, and in 
that case the roof was covered with some kind of 
waterproof sheeting, and a layer of concrete was 
laid over that again, and the roof thus formed, being 
surrounded by low parapet walls, was used as a 
shallow water tank. It was found, however, that the 
water somehow or other got into the room below, 
therefore the water was withdrawn, after which the 
water got through worse than ever. (Renewed 
laughter.) That is to say, every time there was a 



62 THE CONCRETE INSTITUTE 

shower of rain, through it came. An effort was made 
to stop that by covering it over with some sort of 
felt, which was only partially successful. It would 
be very useful to know whether Mr. Workman has 
had any difficulty with his flat roofs, of which he 
appears to have constructed a good many, and what 
solution he has arrived at for this particular problem. 

I should also like to call attention to a paragraph 
in the second page of his paper where he says, " In 
regard to shear I would point out that in the first 
method " (that is to say, in the method of using 
horizontal tension bars with vertical stirrups) " the 
vertical shear is taken up by the main bars and the 
horizontal shear by the vertical stirrups. That is a 
thing that I have often thought about. Mr. Workman 
says that the vertical shear is taken up by the main bars. 
Personally, I am still rather doubtful of that, although 
I have his authority on the matter, because, when 
one comes to think of it, the principal shear stresses, 
both vertical and horizontal, are at the neutral axis, 
and at that point there are no horizontal bars. Of 
course, the horizontal bars are at the lower edge of 
the beam, or in doubly reinforced beams they are 
at the lower edge and the upper edge ; there are 
none at the neutral axis, where the shearing stresses 
are greatest. I would, therefore, feel inclined to ask 
Mr. Workman whether, bearing this in mind, he still 
maintains that the vertical shear is taken up by the 
main bars in cases where there is no inclined rein- 
forcement. 

I gather from this paper, and also from work which 
I have known Mr. Workman to carry out, that he 
is an advocate of the system of having a large 
number of small bars and bending them up, rather 
than having large horizontal bars and using vertical 
stirrups. Certainly, as he says in his paper, it does 
seem the economical thing to do, as the amount of 
steel in tension can be diminished towards the end 
of the beam. On the other hand, it has the draw- 
back that in using a great number of bars one is 
liable to get imperfect concrete round those bars. When 
using a great many small bars, instead of a few 
large ones, you are bound to get those bars crowded 
close together, and the result is that the concrete may 



TWENTY-FIRST MEETING, December 14, 1911 63 

not be quite sound in the very small spaces that 
occur between those crowded bars. I have myself 
cut out concrete in places where bars have been 
crowded, and found that small voids have occurred 
in consequence of the various steel members being 
too close together, and that being so, I always prefer, 
if it is at all possible, to have rather larger sections 
and keep them a respectable distance apart. 

Once more, Sir y I would express our hearty thanks 
to Mr. Workman for all the information he has 
given us. (Applause.) 

Mr. PERCIVAL M. FRASER, A.R.I.B.A. :— Mr. 
Chairman and gentlemen, I have very great pleasure 
in seconding a hearty vote of thanks to Mr. Workman, 
It is astonishing, considering the amount of concrete 
that we all see every week of our lives, the wonderful 
interest it holds for us. I have been quite held in 
rapture to-night to see the various works which have 
appeared on the screen, and we have all learned some- 
thing again, I think, from seeing the works both in 
progress and completed, although only presented in 
pictorial form. 

I notice Mr. Workman still uses the hackneyed 
expression, " This comparatively new material." I do 
ask that we members of the Concrete Institute should 
drop that to some extent now. It may be new in the 
number of years, but surely we are fairly old in our 
experience of it now. I do not think any subject has 
been so closely attacked and so minutely dealt with 
in all its details, practical and scientific, -as reinforced 
concrete. 

I have made a few notes, Sir, in the dark, 
and I have, therefore, some difficulty in reading 
them. (Laughter.) With regard to the com- 
parative methods of the cranked bar and the stirrup 
as for tension strains, I am a very strong advo- 
cate of the stirrup form of construction, both from 
the point which Mr. Wentworth-Sheilds just men- 
tioned with regard to surrounding the whole of 
the members thoroughly with the mixture, and also 
from, I think, a far more important point, that cranked 
bars are most difficult to construct. We have seen on 
the screen to-night the members formed of top and 
bottom rods and stirrups, slung up by a crane and 



64 THE COXCRETE INSTITUTE 

put into position in a way that, I think, would be 
absolutely impossible with a cranked bar. That is one 
advantage. It must be a great economy to handle a 
heavy beam 40 ft. long by means of a crane, and it 
suffers not a whit by being handled in that way. Two 
workmen can carry an ordinary bar with stirrups very 
comfortably indeed and drop it into position, and if 
properly made by winding the stirrup round the top 
and bottom rods, it can be handled and dropped about 
in a most merciless manner with very little deteriora- 
tion. Another objection I have to the cranked bar is that 
you cannot use this economically where there is no slab 
forming a T to take up the compression. 

It has been very interesting to see the photographs 
of the works in Jamaica. They are among the few 
buildings existing where concrete is perfectly treated 
as material fit for an elevation. The effect is obtained, 
not by facing up with stone or brick but by getting 
magnificent effects of light and shade and by 
a general charming proportion . In the case of the 
Hostel, I think at Birmingham, we have seen a photo- 
graph of a slab being concreted, the top of which was 
running with water. I venture to suggest that the 
concrete on that occasion was far too wet. 

Mr. "Workman says that rods are turned up at the 
ends to prevent them slipping in the concrete in conse- 
quence of the new rules of the Joint Committee of 
the Royal Institute of British Architects. I cannot 
conceive of rods slipping in concrete myself. I have 
never heard of a definite case of such a thing happen- 
ing, and the only way I can look on a rod being turned 
up at the end is as a sort of factor of safety against the 
rod being painted or greasy, when it certainly would 
not stick. 

I am driving a few piles next week which are on the 
Coignet system. It is interesting to note in this con- 
nection that I received the order to make these piles 
on Monday, and owing to the able co-operation of 
Messrs. Coignet and the contractor the seven piles 
were ready on Friday evening the same week. These 
piles are 28 ft. long and 12 in. in diameter. 

Mr. Wentworth-Sheilds omitted to mention, in the 
case of M. Francois Coignet's roof on his Paris 
house, that the concrete there was lime concrete ; and, 



TWENTY-FIRST MEETING, December 14, 191 1 65 

in spite of this fact, the steel was found absolutely free 
from rust. 

[Mr. WENTWORTH-SHEILDS here interposed 
that there was a certain proportion of cement also used.] 

I must say, from my experience, that reinforced 
concrete, waterproofed with one of the many com- 
pounds now on the market, gives good results. I have 
constructed a small flat roof (not on the Coignet 
system) ; it consisted simply of hoop -iron placed on 
edge. With regard to the water getting into this flat, 
it had a mixture of Medusa Compound in the upper 
two inches, and it is absolutely watertight. It is quite 
flat, and contains two inches of water, the outlet being 
above the main level. I am also constructing at the 
present moment roofs covering about 70,000 ft. There 
is a 3 -in. fall in 90 ft. in each direction, and no other 
method is taken of covering these roofs except this 
waterproofing compound. I have nothing further to 
add, except to endorse the vote of thanks proposed by 
Mr. Wentworth-Sheilds. (Applause.) 

Mr. CHARLES F. MARSH, M.Inst.C.E. :— I have 
nothing very particular to say, but I am afraid after 
the last speaker's remarks that there is a necessity to 
say something in defence of reinforced concrete. It 
appears that Mr. Fraser prefers vertical stirrups to 
inclined stirrups. 

Mr. FRASER :— Not inclined stirrups. 

Mr. MARSH : — Please correct me, I want to know. 

Mr. FRASER : — I did not use the expression " in- 
clined stirrups " at all ; I do not know them at all. 

Mr. MARSH :— Well, inclined bars. I do not quite 
see the reason for preferring vertical reinforcement. 
It seems to me that the inclined bars are certainly 
equally efficient, if not more so. 

There was also a statement made that the round 
bar never slips through concrete. Well, of course, I 
think it is generally recognised that it is necessary, 
or it is advisable, at any rate, to do something at the 
end of your bar, if you are reinforcing a beam, to 
make some sort of a security to the concrete, so as 
to counteract any tendency of the bar to slip, and I 



66 THE CONCRETE INSTITUTE 

think cases have been known of bars actually slipping- 
through the concrete. I quite agree with Mr. Went- 
worth-Sheilds in not liking the form of the Coignet 
bent -up reinforcement owing to the fact that all the 
bars are tied close together, and there is not suffi- 
cient room between for the concrete to get properly 
round them. 

I noticed one thing in the paper. Mr. Workman 
said that one advantage of the round bars was that 
they were preferable to any other bar from the point 
of view of adhesion. I do not know whether he 
refers to the tendency to slipping. Of course, it is 
hardly fair to any other form o'f reinforcement, such 
as, for instance, deformed bars, to say that round 
bars are better than they. The deformed bar offers 
more resistance than the plain bar from the point 
of view of sliding through the concrete, but the plain 
bar, properly dealt with, offers quite sufficient resist- 
ance in all ordinary cases. 

There is another point of mere correction in the 
paper. Mr. Workman said that the big beams in 
some factory were parallel to the windows. I think 
he meant at right angles to them. 

Mr. WORKMAN :— Yes, at right angles. 

Mr. MARSH :— I do not think I have got any- 
thing else to say. 

Mr. D. G. SOMERVILLE :— I do not know that 
I have anything to say about the matter, but I was 
rather interested in Mr. Fraser's statement that there 
were piles ordered on a Monday and ready to be 
used on the Friday night. I have made a good many 
thousand concrete piles 

Mr. FRASER :— They were ordered on the Monday 
and ready on the Friday. 

A MEMBER :— Was it the following Friday ? 

Mr. FRASER :— No, we never drive piles on a 
Friday. 

Mr. SOMERVILLE :-After that I will sit down. 

Mr. E. FIANDER ETCHELLS, F.Phys.Soc. :-Mr. 
President and Gentlemen, 1 have listened with in- 
terest to the paper, and while the slides were on the 



TWENTY-FIRST MEETING, December 14, 191 j 67 

screen I was very much interested in the background 
of the pictures. It seemed like a holiday tour round 
Great Britain, and a visit to the West Indies, and 
I very much enjoyed it. I was also very pleased 
to notice that the author says that the specialists adopt 
the particular method of reinforcement which they 
think best suited to their purpose. I am glad that is 
stated, because it will correct a very erroneous im- 
pression that the specialists think best of the system 
which they have adopted. Of course, if they did, it 
would only be natural, because that was the system 
which they had studied most and had most experience 
of its good points, and in which they had most 
opportunities of remedying the bad points. 

On page 3 it is stated that a round section pro- 
duces the minimum amount of metallic contact between 
the various bars that form the units or trusses. That 
statement might be corrected, because square bars 
standing corner on corner, i.e., with the diagonals 
running in the same straight line, would afford a 
still greater amount of space for the concrete in be- 
tween the two bars. The angle of concrete would 
be better, if not quite so sharp. Of course, on the 
other hand, there may be disadvantages of adhesion 
against a flat surface ; I am not oblivious of that 
possibility. 

With regard to the suspended floors, they are most 
interesting, and they show one of the new develop- 
ments of this form of construction. One of the finest 
instances in London is at Victoria Station, where a 
concrete platform is suspended, but there it is sus- 
pended by steel rods slung on steel girders. 

Another very interesting illustration was a building 
with flying buttresses and a gallery outside. That 
was a remarkably good building, and looked very 
well. It reminded one of a building which is much 
praised, the King's College Chapel at Cambridge, 
where there are somewhat similar buttresses and the 
same spaciousness of windows. The detail was not 
the same, but the general idea was equally striking 
in both cases. 

Another good illustration was that of a bridge at 
Inverness. That bridge seemed to be well designed 
and very well adapted to its purpose. One of the 

e 2 



68 THE CONCRETE INSTITUTE 

noticeable features was the narrowness of the piers 
in the direction of the stream, so that the waterway- 
was barely restricted at all. It is quite possible, how- 
ever, that the open framework of the thin supports 
might tend to catch floating timber or trees. If that 
should happen the architects, or the persons respon- 
sible for the maintenance of the structure, could easily 
fill in that framework with ordinary mass concrete, 
and thus obviate the difficulty. 

With regard to the bunker in which 2,000 tons 
of material were suspended, we may take it for granted 
that that was really suspended on steel rods buried 
in the concrete. It would be an advantage and of 
interest if the details showing the main reinforcement 
could be given in the TRANSACTIONS, so that we might 
see how such a heavy load is suspended. 

Coming to one or two remarks of Mr. Fraser's, I 
should like to defend the author's statement in which 
he describes reinforced concrete as a comparatively 
new material. It is comparatively new, because wood- 
work was used round the Swiss lakes about six thou- 
sand years ago. In Egypt five thousand years ago 
they were well acquainted with brickwork. Two thou- 
sand years ago they were using concrete in Rome. 
Forged iron was used a thousand years ago in 
Germany. Rolled iron was used in Great Britain four 
hundred years ago, although it is at a later date that 
it was generally adopted and steel substituted. With 
the exception of one or two reinforcements with bronze, 
nearly all the reinforced concrete work of the world 
has been done within the lifetime of some of our 
senior members. Having regard to the long history of 
Structural Engineering and the antiquity of the art of 
building, reinforced concrete is comparatively new. 

THE CHAIRMAN (Sir Henry Tanner) :— Before 
putting this vote of thanks to you I should like to 
express my appreciation of Mr. Workman's address, 
and also of the very excellent series of photographs 
which he has shown, which make the paper far more 
interesting than papers usually are. 

In regard to super-loads on floors, there is no doubt 
that what Mr. Workman says is absolutely correct. 
People do estimate the super -load at very much more 
than it is ever likely to be. We fixed f- cwt. for the 



TWENTY-FIRST MEETING, December 14, 191 1 69 

post-offices referred to, after having experimented on 
the subject. I had a considerable area of floor filled 
up as high as was reasonable with full parcel baskets, 
perhaps about 12 ft. ; that is much more than we are 
likely to get on any floor of that s'ort, and it was found 
that the average load was well within the £ cwt. 
provided for. 

As to roofs, I have never had any trouble with a flat 
roof of concrete. I have always covered them with 
asphalt, but you cannot lay the asphalt in too great 
widths. I think if you have asphalt without some 
means of expansion and contraction in spans of more 
than 40 ft. you are sure to get trouble ; so what I 
have done is to make a small mound in the middle, as 
it were, like a roll of lead, when it has opportunities 
of drawing out of the internal angles. 

Those buildings at Jamaica are of very considerable 
interest ; they are rather new in design and in archi- 
tectural treatment. Probably the plans of the internal 
arrangements have some effect upon this. With those 
remarks I propose to put the vote of thanks. I am 
sure you will carry it by acclamation (Applause.) 

Mr. WORKMAN (replying to the discussion) :— 
Mr. Chairman and gentlemen, I must first of all thank 
you very much for your very cordial reception of my 
paper, and I wish to thank Mr. Wentworth-Sheilds 
and Mr. Fraser. I now propose to take up some of 
the points of the various members who have been kind 
enough to make some remarks. 

First of all, Mr. Wentworth-Sheilds has asked me 
to describe the driving of the piles at Bristol. These 
piles were not driven with a helmet ; they were 
driven by means of a wooden dolly 18 in. in height 
and made of elm, the top and bottom of the dolly 
being encircled by a steel band in order to prevent it 
from splitting. Underneath the dolly sawdust was 
placed on the top of the pile, and held in by means of 
a little casing of sheet -iron to prevent it from flowing 
out ; the wooden dolly was placed on it. The saw- 
dust, however, after a few blows, was found to get 
absolutely as hard as the wood of the dolly itself, so 
we had to use something else. The next thing resorted 
to was coils of rope made into a kind of little mat 
and placed on the top of the wooden dolly ; then the 



70 THE CONCRETE INSTITUTE 

steam hammer was placed on the top of the wooden 
dolly. In this way the piles were driven without any 
difficulty whatever. I have been informed lately that 
there is' an advantage in driving with a helmet. We 
have never used any helmet, because it is rather an 
expensive apparatus, and so far we have always been 
able to do without it ; but I am informed by con- 
tractors — and I give you the benefit of this information 
—that they believe the helmet is an improvement. That 
is all I can say about it. I do not know in what way 
it is an improvement ; I am told it prevents the head 
from being battered, but I have never seen much 
objection to the head of the pile being battered, 
because, as a matter of fact, in most cases you have 
to chip the concrete at the head of the pile to unite 
it to some beams or some foundation supporting the 
columns . 

Now, with regard to Mr. Wentworth-Sheilds's re- 
quest that I should describe the reinforcement of the 
four central pillars for the sorting-office of the 
Western District Post Office, as far as I remember 
it was composed first of all of four bars in each corner 
of the pillar and two intermediate bars between those 
four bars, so that inside the column you would have 
altogether eight bars of about I in. in diameter, and 
those bars were bound by means of y-in. helical ties 
placed about 6 in. apart. 

I would take this opportunity to mention a thing 
which may be of interest to those dealing with very 
large columns in reinforced concrete. It is necessary 
when designing a very large column to have a con- 
centric row of bars in the centre of the pillar, and 
I remember very well that the question was discussed 
when we designed the reinforcement for these par- 
ticular pillars at the Western District Post Office as 
to whether there would not be some advantage in 
placing the bars in the centre as well as on the peri- 
phery of the pillar. We came to the conclusion, how- 
ever, that we could do without that. We simply placed 
the bars in the manner I have described, and, as a 
matter of fact, this proved quite satisfactory, not only 
in this case but in many others. I may say here that 
these are by no means the heaviest pillars which I 
have had to deal with. For instance, all the pillars in 



TWENTY-FIRST MEETING, December 14, 191 1 71 

the second tobacco warehouse support 300 tons, and 
they were constructed in the same manner as those of 
the Western District Post Office. 

Mr. WENTWORTH-SHEILDS :— Is it for con- 
structional reasons that you have got a concentric 
row of steel rods ? 

MR. WORKMAN :— It is thought that if another 
concentric row is placed in the centre of the pillar, 
it reinforces the core of the concrete pillar better 
than if you place all your steels on the periphery 
only . 

Now, concerning the suspended beams, I have en- 
deavoured in my paper to describe how those beams 
were suspended to an upper beam actually above the 
floor level, but I admit that on reading my paper 
over again I was astonished to find how difficult it was 
to make it clear without showing drawings, and I 
wanted as much as possible in this lecture to avoid 
showing drawings, because I wanted to show you 
photographs only. I will try to briefly explain how 
these beams were suspended. The suspended beams 
were placed at right angles to the beam above, so 
that these lower beams were bodily supported by 
means of straps or stirrups hooked on to the tension 
bars of the lower beams, and penetrating into the 
upper beam, and hooked into these. Of course the 
straps or stirrups suspending the lower beams had to 
be calculated of sufficient strength to carry, not only 
the dead load of all this mass of flooring with the 
beams, but also the superload, and as I said in my 
paper, although I endeavoured to find out whether 
anybody else had ever done this before, I could not 
find that anybody had. Mr. Etchells mentioned, I 
think, that he had seen at the Victoria District Railway 
Station a platform suspended in that manner. I have 
seen it, but that is in steel work, while what we were 
doing was reinforced concrete, and, as I say, I could 
not find that it had been done before. 

MR. WENTWORTH-SHEILDS :— Excuse me ; were 
the suspending links passed right over the upper rein- 
forcement, or an upper beam, or merely over the 
tension reinforcement of the upper beam ? 



72 THE CONCRETE INSTITUTE 

Mr. WORKMAN :— No, the straps were simply bent 
over in the concrete like a hook, simply to form a 
sufficient anchorage in the concrete. 

Mr. WENTWORTH-SHEILDS :— About half-way 

up the beam or something like that ? 

Mr. WORKMAN :— Right to the top. Now, con- 
cerning the covering of flat roofs, of course, with 
roofs in reinforced concrete, if the covering is not 
properly treated, these roofs are very apt to give 
trouble, and as I am aware the best way is sirnply 
to cover them with asphalt. M. Coignet is of opinion 
that asphalt is not a good material to cover flat 
roofs, because the mineral oil contained in the asphalt 
is liable to evaporate after a certain time, the asphalt 
becomes a dry, dusty material, which then cracks and 
lets the water through the concrete, unless the con- 
crete itself is not a sufficiently strong mixture to be 
water -proof . 

Concerning my remark about the vertical bars 
resisting horizontal shear and the horizontal bars re- 
sisting vertical shear, all I can say is that that is 
what we consider is taking place in these beams . 
Of course, I am quite aware of the fact that these 
efforts are maximum at the neutral axis, and with very 
deep beams a certain number of small bars are placed 
at the neutral axis at the point of penetration of a 
beam into a pillar, but generally the concrete is quite 
sufficient to take a considerable amount of the shear 
itself. 

In answer to Mr. Fraser's question, there is no 
doubt about it that the reinforced concrete is a com- 
paratively new material. It is only within the last 
fifteen years, I think, that it really has been used 
extensively, and of course it is growing in use gradually, 
but at the same time, when we compare it with brick 
and any other form of construction, even steel work, 
we can only say it is a comparatively new material. 
I think Mr. Etchells has come to my rescue and defined 
the situation by citing examples of antediluvian works 
in masonry, but there is no doubt about it, although 
reinforced concrete is making rapid strides, we cannot 
say it is very old. 

Concerning the cranked bars and the frameworks 



TWENTY-FIRST MEETING, December 14, 191 1 73 

made with vertical stirrups, I know Mr. Fraser prefers 
vertical stirrups, and he suggested that the frame 
which was shown in the photograph could never have 
been lifted if it had been made of cranked bars. I 
am sorry to undeceive him, but that particular frame 
is made with cranked bars. The bars being hooked 
on to the top bar, of course it is quite possible to 
lift the unit. 

Mr. Marsh also made some suggestions about the 
two different methods of making reinforcement. The 
reason the system of beams with cranked bars is pre- 
ferable to the system of beams with horizontal bars 
is because the beams made in this manner are more 
elastic. 

I am sorry that time does not allow me to discuss 
any of the other points, nor to give you a description 
of the reinforcement of the bunkers at Kinlochleven. 
The plans are so very complicated that it would be 
absolutely impossible for me to show them on the 
screen and make you understand without going into 
a very detailed description. I must again thank you 
for your cordial reception. 

THE CHAIRMAN :— The date of the next Ordinary 
General Meeting will be January 1 ith, at 8 p.m., when 
discussion will take place on the Report of the Rein- 
forced Concrete Practice Standing Committee on the 
Standardisation of Drawings for Reinforced Concrete 
Work. An Interim Report of the same Committee on 
" Consistency of Concrete " will also be submitted for 
discussion. 

The meeting then terminated. 



TWENTY -SECOND ORDINARY GENERAL 
MEETING 

Thursday, January i i, 191 2 

THE TWENTY -SECOND ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
on Thursday, January II, 1912, at 8 p.m., in the 
Lecture Hall at Denison House, 296, Vauxhall Bridge 
Road, London, S.W., 

Mr. F. E. WENTWORTH-SHEILDS, M.Inst.C.E. 
(Vice-President of the Institute;, in the Chair. 

THE CHAIRMAN :— Gentlemen, I have first to read 
out to you the names of those who have applied for 
membership of the Institute. 

The following were then duly elected members : — 

Mr. Peter B. JAGGER, Director of the Improved 
Construction Company, Westminster. 

Mr. James M. KESSOX, of Alwen Reservoir, Cerrig- 
y-druidion, near Corwen, North Wales. 

Mr. L. S. Rudman, Civil Engineer, London. 

THE CHAIRMAN (Mr. WENTWORTH-SHEILDS) :— 
I will now ask Mr. Vawdrey to read to us two very 
interesting Reports which have been prepared after 
much careful thought by the Reinforced Concrete 
Practice Standing Committee of this Institute, of which 
he is Hon. Secretary. The first one deals with " The 
Standardisation of Drawings." This Report, I may 
mention, has already been published in the TRANS- 
ACTIONS of the Institute, but this is the first time we 
have had an opportunity of discussing it. The second 
is perhaps even more interesting, and is on the very 
important question of the " Consistency of Concrete." 
Mr. Vawdrey, as Secretary, has taken a lot of trouble 



TWENTY-SECOND MEETING, January ii, 1912 75 

in connection with these reports, and I will ask him 
to read them, and to give us any views on the subject 
that he has himself. 

Mr. R. W. VAWDREY, B.A., Assoc. M. Inst. C.E., 
then read extracts from the Report on " The Stan- 
dardisation of Drawings of Reinforced Concrete 
Work." 

Continuing, Mr. VAWDREY said : — In connection 
with that Report, there are one or two remarks I 
should like to make. It is clearly desirable, I think, 
that some sort of uniformity — as much as possible — 
should be attained in drawings, but I suppose all 
rules are only meant to be broken, and it is quite 
impossible for any large drawing -office to insist on 
any such rules as those which have been suggested 
being absolutely adhered to. The object of the Report 
is to encourage the same style and methods rather 
than to insist upon, or attempt to recommend the 
insistence upon, any details. 

My own personal opinion is that anything in the 
nature of colouring on drawings for reinforced con- 
crete work, which are necessarily more or less intricate, 
should be avoided, and I should like to lay, person- 
ally, more stress on that point than is made in the 
Report. The same personal opinion applies to the 
marking to show concrete. So far from making 
matters clearer, my own experience is that it makes 
matters very much the reverse to attempt to show 
concrete by dots or hatching or anything of that sort, 
especially with a view to reproduction of drawings. 
I think everything should be either in black and 
white or solidly blacked in. 

The system of symbols, I think, is a good one, but 
the whole object of a system of symbols such as we 
suggest is that they should be perfectly intelligible 
to everybody. That, I am afraid, would not be the 
case if they were suddenly taken into general use at 
the present moment ; but in any drawing-office in 
which a particular system of symbols, such as that 
suggested, can be used, the advantage in saving of 
space on the drawings and saving of time is very 
marked. 

The same thing applies to standard lettering. I am 
afraid it is quite impossible to hope that any standard 



76 THE CONXRETE INSTITUTE 

lettering can be universally adopted, but if in any par- 
ticular office that can be gradually brought about— the 
process must be gradual— it certainly must be a very 
great advantage. 

The next Report I am to read is the Interim Report 
of the Reinforced Concrete Practice Standing Com- 
mittee on "The Consistency of Concrete." 

INTERIM REPORT OF THE REINFORCED CON- 
CRETE PRACTICE STANDING COMMITTEE 
ON THE CONSISTENCY OF CONCRETE. 

A circular letter of inquiry on the subject of 
the Consistency of Concrete was addressed to the 
members of the Concrete Institute, in which it was 
suggested that a specification as drafted would be of 
service, pending experiments and tests that ought to be 
made to determine the exact proportion of water to 
be used in concrete in order to obtain the best mixture. 
This specification, as now slightly modified by the 
Committee, is as follows : — 

Consistency of Concrete. — For mass concrete 
the quantity of water added to the other con- 
stituents shall be sufficient to make a plastic 
mixture which, after thorough ramming, will 
quiver like a jelly. 

For reinforced concrete the quantity of water 
added to the other constituents shall be such that 
the plastic mixture is capable of being rammed 
into all parts of the moulds and between the bars 
of the reinforcement. 

Note. — In dry or hot weather the quantity of 
water shall be increased in order to allow for 
evaporation. 

Fifty -eight replies were received, from which a 
number of extracts are appended hereto. 

The replies have been carefully considered by the 
Reinforced Concrete Practice Standing Committee, who 
have come to the following conclusions : — 

I . It is inadvisable to lay down any definite rule 
as to the percentage of water to be used in 
mixing concrete, owing to the varying conditions which 
obtain. The proposed specification is difficult to 



TWENTY-SECOND MEETING, January ii, 1912 77 

improve upon, and seems to meet with general 
agreement. 

2. The strength of concrete apart from any rein- 
forcement increases as the amount of water used in 
mixing is decreased, this being more particularly the 
case during the earlier stages of the maturing of the 
concrete. Eventually the wetter of two mixtures will 
approach more nearly to the drier in strength. 

3. In reinforced concrete, particularly in such por- 
tions as may contain a large amount of reinforcing 
bars or the like placed closely together, it is essential 
that the concrete should be sufficiently wet to pass 
between the reinforcing bars, and to thoroughly 
surround every portion of the steel. This should be 
ensured even at the expense of having the concrete 
wetter than would otherwise be desirable. 

Where the reinforcement is not very closely spaced 
it is unnecessary for the concrete to be so wet. 

4. Other conditions being the same, the drier the 
concrete the more quickly will it set and mature. 
This is of importance when there is any danger of 
green concrete being attacked by frost. 

5. The wetter the concrete the greater is the ten- 
dency to contract during the process of setting and 
maturing. Appreciable contraction may sometimes 
continue for a period of several years. 

6. The Committee is divided as to the advisability 
of determining by some means of mechanical test 
the exact degree of " wetness " or consistency of 
concrete after mixing. If some scale of consistency 
were adopted, it would be possible to specify that 
concrete for any particular portion of the work should 
be of such and such a consistency, after mixing. 
This would not, of course, be at all the same as 
specifying that any particular amount of water should 
be used in mixing such concrete, owing to differences 
of atmospheric temperature, aggregate, etc. 

The advocates of the institution of some such scale 
of consistency are of opinion that the Concrete Institute 
should carry out tests on the subject. 

SUMMARY OF REPLIES RECEIVED. 

1. Several correspondents advocate the considera- 
tion of the results of tests before any rule is arrived at. 

2. One correspondent suggests that a table should 



78 



THE COXXRETE INSTITUTE 



be given showing the maximum difference found in 
practice with different aggregates in the usual propor- 
tions and under different conditions, the quantity of 
water to be stated in gallons per cubic yard and the 
moulds assumed to be of soft wood. The form of 
table is as follows : — 

PROPORTIONS OF CONCRETE. 

Gallons of water per cubic yard of materials. 





Sandstones, Oolites, "Common " 
Brick. 

• 


Granites and 

Hard Limestones. 




Aggregate, Dry. 


Aggregate, Wet. 






A. 


B. 


A. 


B. 


A. 


B. 


Dry weather ... 














Wet weather ... 













A = for getting into corners and sticking to steel all over to prevent 
corrosion. 

B = for strength in masses of concrete. 



3. Some correspondents point out that the quantity 
of water required might vary with the character of 
the cement, namely, whether " quick " or " slow 
setting. 

4. A correspondent points out that in one case 25 to 
30 gallons of water per cubic yard of concrete 
has been advised, and in another case 21 to 24 gallons 
per cubic yard of dry material. 

5 . A second correspondent uses one gallon of water 
to one cubic foot of dry material where the aggregate 
is crushed Thames ballast ; in his case, when the 
temperature has been above normal, it has been neces- 
sary to increase the amount up to 25 per cent, of the 
above -stated quantity, and when the reinforcement is 
heavy and ramming difficult, a further supply of water 
is necessary and i| gallons may be needed. 

6. A third correspondent says that usually about 
22 per cent, of the total volume of cement and sand 
or 20 per cent, by weight of these are usually taken 



TWENTY-SECOND MEETING, January ii, 1912 79 

for the quantity of water, but points out that about 
15 per cent, by volume is required to enter into 
chemical combination with the cement and sand, and 
the rest is lost by evaporation, leaving in its place 
undesirable voids in the mass. 

7. One correspondent suggests that the provision 
as to addition of water in hot and dry weather is 
unnecessary, for under such circumstances a certain 
increase would be automatically required to produce 
plasticity, and the loss should be prevented and not 
counteracted by means which tend to impair the quality 
of the concrete. He suggests the substitution of the 
following rule as sufficient to cover all cases : — 

" The quantity of water added to the cement and 
aggregate mixture shall be just sufficient to pro- 
duce a plastic mass after thorough and complete 
mixing." 

8. Another correspondent would prefer to substi- 
tute the following wording for the clauses put 
forward : — 

" For mass concrete as much water should be added 
as the mixture will take without spilling away or 
working up to the surface when the concrete is being 
conveyed to its destination. 

" In the case of reinforced concrete if after ramming 
into position the water works up to the surface, the 
quantity may be considered excessive. Short of this, 
however, as much water as possible should be added." 

9. A correspondent requires the condition " that 
when the concrete is thoroughly rammed into place 
water shall only just appear on the rammed surface." 

10. A correspondent suggests the insertion of the 
word " light " before the word " ramming," as the 
heavy way in which this is carried out, especially in 
reinforced concrete, often results in the boards of which 
the moulds are made springing apart and so allow- 
ing the water and cement to ooze through the joints 
and detract from the final strength. 

1 1 . One correspondent suggests adding in the first 
paragraph the words " and not more than sufficient " 
after the word " sufficient." 

12. It is suggested that emphasis should be laid 
on the fact that the mixture must only quiver like a 
jelly after the ramming has been completed and not 



8o THE CONCRETE INSTITUTE 

before. It is also suggested that it might be advisable 
to state that where absorbent coarse materials are 
used great care should be taken to let them absorb 
all the water they require before being mixed with the 
cement, or having arrived by experiments at the 
amount of water which the aggregates will absorb 
that extra amount of water should be added at the 
time of gauging. It is thought, however, that the 
former practice would be preferable. 

13. One correspondent points out that the words 
" quiver like a jelly " would apply to a small aggre- 
gate and gentle continuous ramming, but that a larger 
graded aggregate would not show the same result. 

14. One correspondent does not favour ramming 
of concrete, preferring " a plastic mixture of the utmost 
possible density, which will flow into position in the 
moulds and round and in contact with the reinforce- 
ment (if any) without ramming other than consolidation 
aided by iron bars or spades." 

1 5 . Two correspondents point out that the danger 
to be guarded against where a plastic mixture 
is advised, is one of loss of homogeneity caused by 
repeated ramming resulting in the larger parts of the 
aggregate going to the bottom, leaving the fine 
particles at the top. 

16. Another correspondent suggests that to the rule 
for reinforced concrete should be added the words 
" but in no case should the water be so much in excess 
as to cause the concrete to be of such consistency that 
when the mould is filled and rammed it has a distinct 
tendency to act as a semi-fluid under the punner." 

17. A correspondent objects to the watering down 
of concrete to the consistency of slurry in order to make 
it run into the centering and round the steel, for the 
average centering is not sufficiently watertight to pre- 
vent a certain portion of the finest material escaping. 
He thinks that attenuated dimensions in reinforced 
concrete work should be avoided, so as to do away 
with the necessity for making the concrete so liquid. 

18. It is suggested that the specification should 
state that for reinforced work the concrete should not 
contain so much water as to cause a large quantity 
thereof to exude during ramming. 

19. It is pointed out that with reinforced concrete 



TWENTY-SECOND MEETING, January ii, 1912 81 

pipes it might be found impracticable to ram the 
mixture into all parts, and for such class of work it 
would have to be of such consistency as to run. 

20. Several correspondents direct attention to the 
prevention of drying in hot climates. The procedure 
adopted by one correspondent is to use very little 
more water in the original mixture, but to shade the 
work from the direct rays of the sun for the first 
twenty -four hours. Then if in small blocks they are 
totally immersed in a shallow tank of water, or if in 
mass concrete the work is covered with wet .sacks 
or reed matting which is kept at the point of satura- 
tion. In either case the concrete is sprayed with water 
twice a day for about a fortnight. 

2 1 . Another correspondent in hot and dry weather 
waters the concrete two or three times daily for a 
week or so. 

22. One correspondent suggests adding the words 
" and absorption " after the word " evaporation." He 
thinks that in hot weather it is possible the false work 
should be watered on the outside unless a little extra 
water be added to the concrete. 

23. A correspondent desires to call attention to the 
legal aspect of the case, which would probably be 
raised in the case of a dispute, and that is the " good- 
ness " or " badness " of the rule. For this reason 
he thinks the personal element must be entirely elimi- 
nated, and the rule or specification should be so 
framed that the results will bs the same irrespective 
of the persons who shall do the work. He suggests 
the making of a wooden box, 5 in. wide by 3 in. 
deep and 6 in. long, with two i-in. square steel 
bars arranged vertically and attached securely to 
one of the sides, which is to be hinged at the bottom 
to the remainder of the box so as to be capable of 
being opened. In use the box would be filled, then 
after a specified length of time turned with the side 
carrying the bars uppermost and opened, when it would 
be found whether the concrete kept the correct form 
of the mould. He suggests that two boxes should be 
used, and that the Committee should consider — 

(a) The size and shape of the boxes. 

(b) The time before the first box is to be opened 

(minimum). 

F 



82 THE CONCRETE INSTITUTE 

(c) The time before the first box is to be opened 

(maximum). 

(d) The amount of ramming (preferably none). 

(e) The degree of fulness of the boxes. 

24. Finally, a correspondent calls attention to a 
different method of mixing concrete which he 
advocates. He first thoroughly mixes one part of 
cement with, say, two parts of very fine clean sand, 
using clean water enough to make a mixture of the 
consistency of thin cream, and then remixes with three 
parts of wet sand coarser than the first. This total 
mixture of 1 : 5 is then mixed with, say, five parts of 
broken stone. He asserts that with the proportions 
mentioned, namely, 1 : 10, the same strength is 
obtained as with that of 1 : 7\ concrete of the usual 
class. 

The principle of the method is the obtaining firstly 
of thorough contact of the cement with every grain of 
the fine sand, which is rendered certain by the large 
proportion of the cement used, thus ensuring that every 
grain of sand is completely enveloped in the liquid 
mixture. A mixture of this consistency is well calcu- 
lated in the remixing to adhere to all the wetted grains 
of the coarser sand, which will take up the super- 
fluous cement and water and leave only that which 
sticks to the surface of the grains of the fine sand. 
He thinks that the fine sand mixture will thus more 
nearly fill the voids of the coarser sand than happens 
in the usual systems of mixing, where many grains 
of sand get washed by the water, while in other parts 
many grains of cement are found stuck together. 

For a stronger concrete the mixture would possibly 
be 1 part of cement to 1^ parts fine sand, and this 
remixed with, say, z\ parts of sand and 3 parts of 
broken stone. Another mixture would be 1 part of 
cement to 1 part of very fine sand ; this remixed with 
2 parts medium sand and again remixed with 3 parts 
very coarse sand ; all finally remixed with 5 parts 
broken stone of different sizes. 

This system only requires about the same amount 
of labour as the common one, because the liquid 
mixture is small in bulk and quickly made. 

Mr. YAWDREY continued :— I would point out that 
the procedure adopted in this case was for the Secre- 



TWENTY-SECOND MEETING, January ii, 1912 83 

tary of the Concrete Institute to issue circular letters 
to all members, and, I believe, to some other persons 
whose opinion was thought to be of value, asking 
them what their practice and advice was with regard 
to consistency, the amount of water which should be 
added to concrete in both mass concrete work and 
reinforced concrete work. 

Mr. VAWDREY then read the Report of the Com- 
mittee down to the paragraph concluding with the 
following words : " who have come to the following 
conclusions," and then interpolated : — 

Roughly, the Committee is unanimous in these 
general recommendations. They are also based, not 
only on the personal opinions of the Committee but 
on the great majority of the replies received. In 
other words, the great majority of the replies received 
from the general members of the Concrete Institute 
coincide with the views of the members of the Practice 
Committee. 

Mr. VAWDREY then resumed the reading of the 
Report, commencing at the words, " It is advisable," 
and continuing down to the words, " fulness of the 
boxes," at the top of page 82, where he again inter- 
polated : — 

That suggestion corresponds more or less in some 
way to the suggestion the Committee themselves made 
in Clause 6, that some form of test should be devised 
by which the consistency of the concrete should be 
obtained. 

Mr. Vawdrey then continued the reading of the 
Report to the end, after which he said : — 

I should like to point out that the chief difficulty 
that the Committee experienced in discussing this 
question was that of describing the degree of wetness 
or dryness required. Of course, the amount of water 
to be mixed with the concrete cannot possibly, I think, 
be defined. I think that is universally admitted. I 
mean, to mention a percentage, so much per cent, 
of water, as a general specification would obviously 
be absurd. It must necessarily vary with the class of 
materials used, with the quality of the cement, with 
the temperature of the atmosphere during the actual 
process of mixing, with the amount of ramming which 

v 2 



84 THE CONCRETE INSTITUTE 

has to be performed, and with the intricacy of the 
work. There are all sorts of conditions which must 
vary, but it might be possible— I think it would be- 
—to devise some easy method of describing the degree 
of plasticity— if 1 may use the expression— which is- 
desirable in the concrete after mixing. That is what 
is suggested in one clause of the Committee's 
recommendations . 

I may say that the Committee was very much divided 
on that question. A good many seemed to consider 
that it would be quite impossible to devise any such 
scale of consistency, and that even if that were done 
it would merely lead to difficulties on the part of the 
contractor, who would be expected to adhere to a 
particular scale on every part of his job — in fact, that 
he would have a lot more tests to pass. But that is 
not my view at all. The whole object of such a scale 
of consistency is to my mind that, if an engineer 
or an architect wants to specify the degree of wetness 
or the consistency of the concrete in one part of a 
building, he may be able to do so easily. He may 
be able to say that in the beams, or any particular 
portion of any beam, he would like the concrete of 
such and such a consistency. 

My own point of view, therefore, is that it would 
be very useful for this Institute to make some sort 
of tests, which would possibly be adopted universally 
as a means of describing the consistency wanted. 

Correspondent No. 10 remarks, referring to the 
ramming, that he wants very light ramming only. 
Personally, I do not agree with that at all. I think 
that too much ramming cannot be done, and his 
objection that heavy ramming often results in the 
boards springing apart and allowing the water and 
cement to ooze through the joints is not a fault of 
the ramming, but a fault of the shuttering. The 
shuttering should be so constructed that it can take 
proper ramming. 

Correspondent No. 13 remarks that only concrete 
mixed with a small aggregate, and on which gentle 
continuous ramming has been used, will quiver, but 
that with a large aggregate you cannot get the quiver- 
ing. I entirely disagree. In a large mass of con- 
crete you certainly can get the quivering condition 



TWENTY-SECOND MEETING, January ii, 1912 85 

which everybody seems to think desirable, even though 
the aggregate is very big. Of course, if you have a 
small reinforced concrete beam, and a few big stones 
in it, you will not get any quivering because the 
stones iwill wedge themselves from one side of the 
beam to the other, but in a heavy block of mass 
concrete you will get exactly the same appearance 
as in a small mass of very much finer concrete. 

In the same way, I disagree entirely with corre- 
spondent. No. 14, who says he objects to ramming. 
I am convinced, both by theory and practice, that it 
is advantageous in every way to have thorough work- 
ing and ramming of the concrete in reinforced con- 
crete work, and in mass concrete work too. 

Correspondent No. 24 raises a somewhat different 
point from that mentioned in the rest of the paper, 
namely, the proportioning of the concrete, but it is 
so very important that we considered it worth while 
to insert his remarks in this paper. I agree entirely 
with what he says, or rather, with the idea which 
underlies his remarks, which is, I think, that ordinary 
concrete is very badly proportioned. The strength 
of concrete obviously depends to a very great extent 
on the strength of the mortar. By mortar I mean 
the fine material in which the larger portions of stone 
are embedded and held together. An ideal concrete, 
I take it, would be one in which there would be no 
mortar at all, or practically no mortar. Of course, 
I am exaggerating now intentionally. The extreme 
on one side would be a lot of particles of broken 
stone which could be so accurately fitted together that 
there would be practically no voids between them. 
That condition might be obtained if a large number 
•of regular cubes, for instance, of stone were accurately 
fitted together. The amount of mortar required in 
that case would be practically nil. On the other 
hand, the average regular stones show approximately 
50 per cent, of voids. 

The cost of the concrete can thus be very greatly 
reduced by the grading of the aggregate, so that the 
total amount of voids is very small. That enables 
the amount of mortar to be reduced, and it is quite 
possible to have a concrete consisting, instead of 
the 4 of stone, 2 of sand, and 1 of cement which 



86 THE CONCRETE INSTITUTE 

is ordinarily specified, say 4 of stone, \ of sand, and 
i of cement. I have actually seen concrete, and I 
have made concrete, of those proportions, which has 
been quite excellent, but, of course, that is dependent 
entirely on the fact that you can obtain an aggregate 
which has such a very small proportion of voids as 
those I have mentioned. In ordinary practical work 
one has to use materials that can be easily obtained, 
and in most cases it is certainly a fact that the stone 
which one gets will have something like 50 per cent, 
of voids in it, in which case the proportions of 4 of 
stone, 2 of cement, and 1 of sand are about right. 
There is no objection, in my view, to greatly decreasing 
the proportions of sand and cement if the amount of 
voids is decreased by proper grading and mixing of 
the aggregate. That, I think, is the principle under- 
lying the mixture suggested by correspondent 24. 

With regard to the general question dealt with 
in the Report — the amount of water — I think the general 
opinion of the majority of correspondents, and cer- 
tainly of the Committee, is that the use of a large 
quantity of water is to some extent a necessary evil 
in reinforced concrete work. With mass concrete, in 
which voids are not so harmful as they would be in 
reinforced concrete, it is, I think, undoubtedly possible 
to get considerably stronger concrete — at any rate in 
its early stages — by the use of a fairly dry mixture ; 
but in reinforced concrete, although assuming one can 
be sure that no voids will exist, even in that case, too, 
it would be advisable to use the concrete as dry as 
possible ; yet the risks of voids and improper contact 
of the steel with the concrete are so great that one 
is almost driven to use a concrete considerably wetter 
than would otherwise be desirable, and in many cases, 
such as the junctions of beams and columns, where 
there is necessarily a very large amount of reinforce- 
ment, it is practically impossible to use any sort of 
concrete otherwise than almost liquid grout or slurry 
as one of the correspondents calls it. Although one 
may be forced, in spite of one's wish, to use concrete 
of that nature in certain proportions, at any rate there 
are many disadvantages besides the corresponding 
weakness of the concrete. 

One has been mentioned — that is, the cracking. It 



TWENTY-SECOND MEETING, January ii, 1912 87 

does appear undoubtedly the case that the wetter the 
concrete is when it is moulded and placed in position, 
the more chances there are of contraction during the 
process of setting, and not only of setting but during 
the process of maturing. 

In my own experience quite recently, I had a case 
in which contraction had obviously been going on 
in a floor of considerable area for three or four years, 
and is to some extent still going on. Of course, the 
amount is almost infinitesimal, but undoubtedly the 
movement of contraction is still taking place. I am not 
referring to a temporary contraction, but a permanent 
maturing contraction, and I think that is the general 
experience of members of the Committee (Applause.) 

Mr. L. SERRAILLIER, M.C.I. :— I have much 
pleasure in proposing a vote of thanks to Mr. Vawdrey 
for the trouble he has taken in the work of this 
Committee. 

The only remark I have to make concerns the first 
paper : I believe there is a method of making sections 
by placing the tracing paper over the back of a book 
in which the cover is rough, and rubbing a pencil 
over the tracing. This will give the appearance of 
hatching and show up the section lines. The method 
is rapid, and allows of blue prints being taken. 

AN HON. MEMBER :— Not on an ink drawing. 

Mr. SERRAILLIER :— On a pencil drawing ; but 
you can do it in pencil on an ink drawing as well. 

THE HON. MEMBER :— On a blue print? 

Mr. SERRAILLIER :— On a blue print, yes. 

THE HON. MEMBER :— Has that a good effect? 

Mr. SERRAILLIER :— Yes. The other matter I 
wished to refer to was the lettering. Mr. Vawdrey 
says the lettering should be as large as possible. Of 
course, the larger it is the more tendency there is 
that the appearance will not be good, unless you use 
stencil plates. I am very much in favour of using 
stencils in drawings, and not block printing. The 
larger the block printing is, the less regular it is, and 
the uglier it appears on the drawing. 



88 THE CONCRETE INSTITUTE 

MR. S. BYLAXDER, M.C.I. :— Mr. Chairman, it 
gives me very great pleasure to second this vote, and 
in particular 'to thank Mr. Vawdrey for the very valu- 
able remarks he has added to the Reports. 

Personally, I am most interested in the first Report 
as regards standardisation of drawings. From my 
experience in America I found that the Americans 
have gained enormous advantage over the rest of the 
world through their standardised method of producing 
engineering work. The thing that struck me most 
was the drafting-room, with standardised methods 
in great detail. Every office of good standing has a 
set of standard tables. These are used throughout the 
office by each member, and this produces uniformity 
in methods and design. 

Further, the title of a drawing is always placed on 
the lower right-hand corner, which is found very con- 
venient in case of reference, when one has, say, forty 
or fifty drawings in a drawer ; one can thus easily find 
the drawing wanted. 

Another thing, which I believe is not quite realised, 
is that the Americans use mostly ^-in. scale plans 
instead of i-in., as is used here. They therefore use 
i -in. scale details instead of i-in. I believe that this 
has been introduced on the drawings, and therefore 
greater accuracy and clearness is required, and in con- 
sequence a greater scale is employed. I only wanted 
to mention this in connection with the Report, as it 
appears therefrom that the i-in. scale would be best. 
Personally, I believe that for steelwork plans or rein- 
forced concrete plans the j-in. scale is a better one, 
providing the size of drawing required is not un- 
reasonable. 

With regard to the ii-in. scale for details, I would 
prefer the i-in. scale, because the architectural details 
in this country are usually made to i-in., and the 
simplest method of transferring from one scale to 
another is by doubling the size. Further, I think the 
3 -in. scale could be used wherever the i-in. scale 
would not be sufficiently large, and as all drawings 
should be fully dimensioned scaling is not required. 

With regard to the list of sizes of drawings, J 
believe it would be advisable to add something with 
regard to the size of order lists. That is a kind of 



TWENTY-SECOND MEETING, January 11,1912 89 

drawing which, I think, will very much be used in 
the future, much more so than hitherto. 

A very convenient size would be a quarter of the 
smaller size mentioned in the Report — namely, 15 in. 
by 10 in. over all, or 14 in. by 9 in. within margin 
lines. You therefore would establish a standard of 
drawings of different sizes, obtained by halving the 
next larger size. 

With regard to consistency of concrete, I think it 
would add very greatly to the value of this Report if 
a definite quantity of water could be determined for, 
say, London practice or English practice for the stan- 
dard concrete now accepted — viz., 1 cement, 2 sand, 
and 4 crushed gravel. I do not believe that the 
quantity of water would need to be varied much under 
ordinary conditions. 

Mr. Chairman, I thank you for allowing me to 
second the proposition. (Applause.) 

THE CHAIRMAN (Mr. Wentworth-Sheilds) : 
—The discussion is now open. We have heard two 
very interesting Reports, and I am sure we have all 
a good deal to say on one or both of them. 

Mr. E. P. WELLS, J. P., M.C.I. :— Mr. Chairman, 
I had hoped this evening to see a very much larger 
attendance, especially as we combine in these Reports 
the standardisation of drawings and the consistency of 
concrete. 

In reference to the first Report of the Reinforced 
Concrete Practice Standing Committee, it is prac- 
tically a unanimous one. Of course, there are certain 
variations that one would have liked to have seen, but 
it is an impossibility to satisfy the views of all. Taking 
it generally, I think the Report is one which might 
be adopted in this country. 

Personally, I do not like to see all drawings neces- 
sarily the same, as it to a very large extent causes 
individuality to disappear. 

With regard to scales, taking the general type of 
drawing that one has to use, the i-in. is very good 
for plans so long as there are no complications what- 
ever. If you have plain, straightforward work, then 
you can get on to the ith scale plan everything that 
is necessary in the shape of reinforcing, and there is 
sufficient room also to 'state what the beams are com- 



9 o THE CONCRETE INSTITUTE 

posed of ; but if it is a case of varying spans, both 
of floors and beams, then I often find that the £th is 
too small, and I invariably adopt £. 

With regard to elevations for walls, j-in. is suffi- 
ciently large practically to show everything, unless 
there happen to be any architectural features requiring 
to be incorporated into the reinforced work, when the 
i-in. becomes too small. For beams and columns 
1 think, as a rule, the jr-in. is ample, because all the 
reinforcing can be shown in thick lines, which, when 
reproduced, come out very boldly, especially in the 
ferro-prussiate prints. 

For sections of beams and columns I prefer the 
H-in. scale ; I have been in the habit of using it in 
all steelwork design for many years, as it makes mul- 
tiples of fths and f-in. At any rate, it is sufficiently 
large to show everything, and as a rule, I think, is 
preferable to the i-in. 

Occasionally I find it necessary to use full size 
where there is great complication in rods, and where 
practically grout has sometimes to be used you cannot 
do anything else. 

As to the size of the sheets, I like to adhere to the 
Imperial size, but I never, if possible, get outside the 
Double Elephant. If I have to do so, then I get the 
Double Elephant breadth by the Antiquarian length. 

A plan which I have adopted, and which comes in 
very handy at times, is to take some of the general 
work which is existing and put that in, in pencil, 
with the reinforced work in ink. The result is exactly 
the same as working in two colours, in red and black, 
and it distinguishes the new work from the old, and no 
mistake can possibly be made in the matter. 

With regard to sections, and the question which has 
arisen about showing the concrete, I prefer it in all 
work, because once it is done there is an end of it. 
It is not as in the olden days, when one had to trace 
everything. Now one tracing is made, and it is 
always reproduced. 

With regard to the last Report on the consistency 
of concrete, it is a very well-known fact that the 
drier the concrete, and the more it is rammed, the 
greater the compressive strength, but the whole 
resolves itself purely into a question of labour. 



TWENTY-SECOND MEETING, January ii, 1912 91 

With regard to reinforced work, especially if there 
are a number of small members within a beam, it 
is not advisable to do too much ramming. Nothing 
is to be gained by it. If the mixture is made too dry, 
you will never get the proper adhesion between it 
and the steel. Therefore it is advisable to make 
the concrete of such consistency that practically when 
it is in a heap it will not run. This means that, if you 
use Thames ballast in your aggregate and Thames 
sand for the mortar, it requires about ~j\ to 9 per 
cent, of water, according to the time of the year, 
which is required to be added ; but if bricks are used, 
or sandstones, or oolites, which will take up about 10 
per cent of water, then it is advisable to let the 
aggregate take up all the water that it will contain 
before it is mixed with the sand and cement, which 
ought then to be mixed dry, after which about 6 to 
7 per cent, of water is all that is necessary to give 
an absolutely perfect consistency to the concrete. 

With regard to the bricks, it is an absolute necessity 
to wet the bricks first if you require to get a really 
good homogeneous concrete. 

There is one point, while I am on the subject, which 
I may take the opportunity of saying, and that is with 
reference to the use of Fletton bricks in concrete. I 
wish to call the attention of every member of the 
Concrete Institute to the great danger he runs in using 
Fletton bricks in the making of concrete. It only 
came to my notice about two or three months ago in 
some work that I designed for a gallery to a church, 
and within a fortnight after the gallery had been 
finished it started to blow all over the place, and in 
every case where it was opened out it was found to 
be a piece of Fletton brick that was the cause. Last 
week at the meeting of the Committee, Mr. A. C. Davis 
showed some photographs of concrete which had been 
made of Fletton brick, and within one week after 
being made it had blown all over the place and dis- 
ruptured the concrete. Analysis of the Fletton brick 
disclosed an enormous excess of sulphuric anhydride. 

Mr. Davis had the same experience with the bricks 
made from the same formation, and they had disrupted 
the concrete. There is no doubt about it, now that 
Fletton bricks are becoming generally used in London, 



<)2 THE CONCRETE INSTITUTE 

that one will have to be very careful, if brick concrete 
be used, that one does not get the Fletton bricks mixed 
up with other aggregates. 

AN HON. .MEMBER :— Might I ask if they were 
new bricks, or bricks which had been used ? 

Mr. WELLS :— I could not tell you what age the 
bricks were, but Mr. Perkins, the District Surveyor 
for Holborn, told me that he had seen a heap of Fletton 
bricks that had been in the open air for six months, 
which had simply crumbled to pieces and been blown 
and disrupted in every quarter. 

I have not only heard this from two or three sources, 
but from more, and in speaking the other day to a 
foreman of works, he said it is a known fact that 
Fletton bricks put into concrete will always blow. I 
believe that the clay that surrounds Peterborough 
has intrusions of the blue lias formation which is 
found between Rugby and Cambridge, and this would 
account for the blowing. An excess of lime has got 
into the brick, and it has not been properly calcined. 
Of course, that is a matter for experts to go into, 
but from what I have seen lately it seems to be a very 
dangerous practice to use any Fletton bricks in con- 
crete without properly examining the same. 

I intended at the last meeting to say something 
about it, but now the opportunity has cropped up I 
think it is as well to let it be known, because others 
may have something to say on the matter, and it 
will never do to go on making reinforced concrete, 
or even mass concrete with any material where we 
know there is likelihood of mischief taking place. 

With regard to concrete made like slurry ; there 
is an ernormous difference in the strength. I made 
some experiments a few years ago, where, with one 
specimen which was made with an excess of water 
and was little better than slurry in consistency (it 
ran all over the place and it had to be poured into 
the mould), at the expiration of three months the 
crushing resistance was 180 tons a square foot, whereas 
a proper plastic mixture of concrete made at the same 
time went up to 300 tons a foot. 

As I have said very often before, with regard to 
the amount of moisture, it all depends. If you want 



TWENTY-SECOND MEETING, January ii, 1912 93 

to get a cheap concrete and save your labour, you 
must let the water do the work. If you are not par- 
ticular as to labour and can spend the money, then 
lessen the water and put in the labour. Then you 
will get greater strength, especially in short periods. 
You will get a strength in seven days with a very 
dry mixture which would take a month with a 
moderately wet one ; and if you want it to harden 
quickly, then the drier it is made, and the more 
ramming it gets the better, especially in wet weather. 
(Applause.) 

Mr. D. B. BUTLER, A.M.I.C.E. :— I should like 
to confine my remarks more particularly to the Report 
on the " Consistency of Concrete." It must be borne 
in mind, I think, that in adding water to concrete, the 
water has two functions to perform. The first is, 
of course, the chemical function of enabling the cement 
to set, and to form certain combinations. The second, 
is that the water acts as a lubricant which enables the 
various constituents of the concrete to flux or settle 
down into their places when they are rammed or 
shaken. 

I may say that the percentage of water required 
for chemical combination is probably not more than 8 
or 10 per cent, of the weight of cement used, which is 
obviously an impossibly small quantity for practical 
purposes, since if insufficient water is used in gauging 
to produce proper lubrication, the concrete will never 
flux properly into position, and will be weak and 
porous. 

I wish to congratulate the Committee on what I 
may call their common -sense recommendations, and I 
quite agree with them in No. 1, that it is inadvisable 
to lay down any definite rule as to the percentage of 
water that should be used. That, perhaps I may be 
again allowed to say, is entirely common sense, because 
the conditions must vary in every instance, first of all, 
with the cement used, and, secondly, with the kind 
of aggregate used ; climatic considerations must also 
be taken into consideration. 

In recommendation No. 3 it is stated that the con- 
crete should be sufficiently wet to pass between the 
reinforcing bars, and to thoroughly surround every 
portion of the steel. Well, of course, that again is 



94 THE CONCRETE INSTITUTE 

obvious. Some time ago I was professionally engaged 
in a case in which some reinforced concrete piles 
failed, owing to the concrete being gauged too dry- 
in making them. The pile, when it was driven, 
fractured and split, and the contractor, as usual, laid 
the blame on the cement. Examination of these piles 
and of the reinforcement showed that the concrete 
was made so dry that only about a quarter, or perhaps 
a third, of its surface was in contact with the reinforce- 
ment, thereby altogether nullifying the junction of 
the latter . 

I was greatly interested with Mr. Wells's remarks 
about the use of broken Fletton bricks in concrete, 
and the failure resulting therefrom, but I really do 
not quite understand — without wishing, of course, to 
doubt his authority as to the composition of the bricks 
- — how there could be ij per cent, of sulphuric 
anhydride in them; 17 per cent, of sulphuric an- 
hydride would correspond to somewhere about 25 per 
cent, or more — 30 per cent, perhaps — of calcium 
sulphate . 

Mr. WELLS : — 22^ per cent, of calcium sulphate. 

Mr. BUTLER : — Well, I cannot conceive any brick 
standing for even a month exposed to wet with all 
that amount of calcium sulphate in it. W T e all know 
that calcium sulphate, or plaster of Paris, is absolutely 
non-hydraulic ; it goes to pieces in water, and I can- 
not conceive any brick containing that amount of 
calcium sulphate. If it did contain that amount, I 
can quite understand Mr. Wells's remarks as to the 
concrete blowing, because it is a well-known fact that 
if there is much calcium sulphate either in the aggre- 
gate or in the cement, it will cause blowing. I myself 
have more than once met with cases in which old 
bricks with plaster adhering have been used as aggre- 
gate, and it has caused disintegration of the concrete. 
I shall therefore be very glad to receive from Mr. 
Wells a copy of the Report. 

MR. WELLS :— I will send it round, and I will ask 
Mr. Davis to send you photographs of the brick 
showing the state, and also results in the concrete. 
I will ask Mr. Perkins also to do the same. 



TWENTY-SECOND MEETING, January ii, 1912 95 

Mr. BUTLER :— Thank you. 

Mr. P. M. FRASER, A.R.I.B.A., M.C.I. :— Mr. 
Chairman and gentlemen, I have very great pleasure 
in adding my thanks to those which have gone before to 
Mr. Vawdrey as representing the Committee. I have 
not much to say with regard to standardisation of 
drawings, except that the two scales which he rather 
deprecates, the j-in. and the i-in., I agree with a 
previous speaker are the two most useful scales that 
could possibly be employed. I am speaking, of course, 
as an architect, and Mr. Vawdrey did not make it 
quite clear to what type of drawing he was referring. 
There are two real types of drawing in connection 
with reinforced concrete building. The first is the 
architectural drawing and the second is the reinforced 
concrete drawing, and to a certain extent they are 
separate. I use the j-in. scale always for plans of 
buildings covering up to 25,000 ft. super. It is said 
that drawings of that size are too large, but they can 
be cut in half or in quarter, and there is not the 
slightest objection to cut them up to any size you like. 
It is often a great convenience to have your drawings 
cut up ; and if you have any question to settle on any 
part of the building you can take a small portion of 
the drawing, which is easily handled, about 2 ft. 
square, to that particular part. You do not generally 
walk about the building with drawings under your arm. 

With regard to the consistency of concrete, a subject 
in which I am very much interested, the last speaker 
mentioned piles which were mixed too dry. Well, I 
had a case two or three weeks ago of five piles which 
were wanted in a great hurry. In fact, I mentioned 
these particular piles at the last meeting here. They 
were mixed very dry. The contractor, when I 
approved of the consistency of the concrete, was quite 
aghast. He said, " It looks like the inside of a Stilton 
cheese, and I am sure it will fall to pieces." These 
piles were driven in twenty-six days. After making, 
they were driven with a 30-cwt. monkey with a 5 -ft. 
drop ; and although the heads fractured rather, there 
was not the slightest appearance of fracture at any 
part of the pile except just under the head. 

The word " plastic " used in this Report is rather 



96 THE CONCRETE INSTITUTE 

a misnomer. I think concrete cannot be plastic. 
Plastic means that which is capable of being modelled 
or moulded. It is quite opposed to something capable 
of being cast, and I think on strict grounds in a formal 
Report the word " plastic " should be superseded by- 
some other word. 

Also the word " ramming." Ramming presents, to 
my mind, the action of striking heavy blows with a 
heavy tool, and in reinforced concrete I think this is 
quite wrong. You cannot get that artificial strength 
which we all know concrete will obtain which has 
been consolidated during its setting. You cannot get 
that by ramming ; you get disruption more than in- 
creased strength. The only ramming, so-called, which 
I should recognise consists of poking with an iron 
rod, and nothing in the shape of a heavy weight. 

The suggestion " quivering like a jelly " is one 
which I always take exception to. A jelly does not 
quiver on account of fluidity ; it quivers on account 
of its elasticity, and when it is in the mould it does 
not quiver at all, and cannot be made to quiver. The 
words " like a jelly " seem to be quite superfluous 
there. When you say, for instance, " after thorough 
working should quiver," you say quite enough there, 
I think. 

As I have already indicated, I am very strongly in 
favour of a dry concrete. The Committee, although 
they do not actually uphold wet concrete, seem to 
imply that the wetter a concrete is, within certain 
limits, the better. I take the view that the dryer it is, 
within certain limits, the better. The moral of para- 
graphs 2, 4, and 5, with regard to the ordinary 
strengths of wet and dry concretes compared, is to use 
your concrete dry and get your ultimate strength as 
soon as you can, putting on one side the fact that wet 
concrete will never get the same eventual strength as 
a dry concrete ; and where the reinforcement is par- 
ticularly complicated, you do not get over that com- 
plication by using a wet concrete, whereby a sort of 
mud gets underneath the bars and a mass of large 
stones gets on top of the rods. One wants to use a 
fine concrete at these points, bringing it down to -}-in. 
stuff, or ij-in. at the outside, and supervise at those 
points as much as one can and see that they are 



TWENTY-SECOND MEETING, January n, 191 2 97 

properly punned. One of the correspondents inquired 
whether a greater amount of water is required for 
a quick or slow-setting cement. I have not had any 
experience of that, and I shall be very glad if any 
gentleman here will give us any information on that 
point. 

A suggestion is put forward that sand and cement 
should be mixed dry and then wet, and then mixed 
with the aggregate later on. Anybody who has seen 
that process actually carried out, I think, will bar it 
once and for all. It is a most painful thing to watch, 
and it costs, I suppose, five shillings a yard more for 
labour ; and I am sure the result, except in perhaps 
one or two very elaborate mixing-machines, must be 
very bad. 

There are a few rough-and-ready methods of 
telling whether the consistency of concrete is right. 
If you load concrete into a barrow, by the time it is 
wheeled into its place, it should not have taken a 
horizontal surface. You should be able to take a 
shovelful of concrete from the bank and hold it at 
a slight angle, and it should show no signs of the 
cement dripping away. Also you should be able to 
make a hole in the concrete in the barrow which no 
amount of ordinary vibration should ever cause to 
fill in. 

In conclusion, I should just like to read an extract 
from one of our leading technical journals, which I 
think may amuse, if it does not instruct you. It is 
an editorial which says : "A correspondent thinks the 
following extract from a specification lends itself to 
innocent mirth : — 

' The concrete to be carefully packed over and 
between the bars and well rammed until the mass 
quivers like a piece of liver.' " (Laughter.) 

The Editor goes on to say that this suggests a 
simple rhyme which can be committed to memory 
by a foreman, clerk of works, or others interested in 
the question of consistency of concrete, namely :— 

" Let the concrete be carefully packed 
Between and right over the bars, 
Well rammed and judiciously thwacked ; 

Till, under the consequent jars, 
It shall sheenily shudder and shiver 
Like a lump of resilient liver." 

(Renewed laughter.) 



98 THE CONCRETE INSTITUTE 

MR. THOMAS POTTER, M.C.I. :— I have jotted 
down a few notes from my own experience. Where 
the aggregate is of one kind and consistency, there 
is obviously no difficulty in ascertaining the amount 
of water required, assuming that the aggregate is 
not some dry and some wet. In an ordinary way 
there are many difficulties to contend with. The 
aggregate may be of a porous nature and absorb a 
good deal of water, or it may be gravel, which would 
practically absorb none. Then, a small aggregate 
requires more water than a larger one. It may have 
to be washed, and would then require a less amount 
of water than if dry. It depends, too, upon the purpose 
the concrete is for. 

For monolithic walls it cannot be rammed or com- 
pressed between the forms to any extent, or the form 
boards may be pushed out of place. For floors it 
can be beaten or compressed. As a result, more water 
is required for concrete for walls than for floors. 

If too much water is used, the excess may carry 
away with it some of the cement, and is in evidence 
as the water, not necessary for hydration, comes 
through the joints of the form boards of floors and 
walls. The water parted with in this way should be 
quite clear. 

For floor purposes, if too much water is used, it 
comes rapidly to the surface when beaten or com- 
pressed, and cement adheres to the surface of the 
beater. Violent beating of the concrete, except when 
it is in large mass form, causes the water and cement 
to quickly come to the surface, which is avoided if 
the impact is of a gentle character and quickly per- 
formed . An intelligent foreman will soon ascertain 
how much water is essential for the purpose it is 
required for. If too little is used, the finer portions 
of the aggregate do not slide into place readily, and 
the concrete is not homogeneous ; if too much is 
used the water that escapes will take with it some of 
the cement . 

The amount of water necessary is one of those 
things very difficult to standardise for general 
practice. I prefer the personal equation in deter- 
mining the amount, assuming a capable man directs 
the work. 



TWENTY-SECOND MEETING, January ii, 1912 99 

When the aggregate has to be washed previous to 
and at the time of use, and is of a non -absorbent 
character, but containing mud or clay, as gravel from 
sluggish streams, or pits where it contains clay, a 
very small amount of water is necessary for mixing 
purposes. 

Mr. E. FIANDER ETCHELLS, F.Phys.Soc, 
M.C.I. : — Mr. Chairman and gentlemen, with regard 
to the first Report, I should like to supplement a few 
of its requirements. I would not make them obliga- 
tory, but they are merely one or two hints or sugges- 
tions by which the drawings, when standardised, would 
be more quickly and more readily intelligible to those 
who had to interpret them. First, it would be desirable 
that the prints or drawings should be indelible black- 
line photo prints on white linen. The white linen 
will enable any alterations or additions to be readily 
shown, and that cannot be done with the blue prints. 
Another objection to the blue prints is the danger to 
one's eyesight in examining them day after day and 
hour after hour in a dark, foggy place like London 
so often is. Mr. Serraillier made a suggestion with 
regard to hatching on blue prints, and I also would 
like to give another which, although old, may never- 
theless be new to a few of the members. It is that 
with a blue print, which is difficult to trace, it can 
be laid over a thick sheet of plate-glass with the 
ordinary electric light behind it, and it will then show 
up very plainly and can be traced readily. I would 
also suggest that any tracings which should be made 
should also be made on the unglazed side of the linen, 
the reason being again that any pencil-notes can be 
readily made, and that is difficult on the glazed side. 
Then, again, if the scale on which the drawings were 
made were drawn on as well as being described in 
words it would be a double advantage ; you would have 
a greater freedom in selecting your scale. If the scale 
were drawn in two directions at right angles to each 
other, it would not matter so much how the print ex- 
panded or contracted during the process of reproduc- 
tion. With the linen prints particularly they are not 
always true to scale, but with two scales, one perpen- 
dicular and one drawn horizontal, you can get a very 
fair idea of dimensions when all the measurements are 
not given. 

g 2 



ioo THE CONCRETE INSTITUTE 

It would also be desirable that the north point should 
always be indicated on all plans, and also all plans of 
the same building should have the north point leading 
in the same direction as far as practicable. Then you 
can lay one plan over another. Much time is lost 
and much annoyance caused in having to twist the 
plans of complex buildings round and round to find 
which way they are to go, and to compare one with 
another. 

All sections should bear the title or reference, clearly 
indicating the position of the section plane and the 
direction of the point of view, etc. ; and also it would 
be desirable that all views should be projected from 
one another, as far as possible, and be placed in the 
geometrically correct planes. There is very little mis- 
take ever made with regard to the plan of the front 
elevation, but the principles by which those have been 
deduced should be extended to the side elevations, and 
from that it follows that the left-hand elevation will 
be projected on to a plane at the right-hand side of 
the plan and vice versa. Some confusion is occa- 
sioned by those who have learned to draw before they 
have studied geometry, and who persist in placing 
the left elevation on to the left side. I express the 
hope that those who make the drawings will keep in 
mind the Universal and International Conventions of 
Geometry in this particular. 

When details are not projected from one to another, 
or where they are not closely related, then there should 
be a greater space between the separate views, so 
that the eye can readily perceive to what part the 
details appertain. 

Another desirable feature in reinforced concrete 
drawings would be that the proportion and nature 
of the concrete and the minimum crushing load at one 
month or at three months should be clearly indicated 
on the plans. We naturally expect to find it on the 
specification, but with the amount of specialisation 
which exists at present the specification and the plans 
seem to part company and fall into different hands, 
or we do not see them at the same time. 

With regard to the second Report, I also object, as 
one of the previous speakers did, to the references to 
table delicacies in an engineering definition, and I would 



TWENTY-SECOND MEETING, January ii, 1912 101 

eliminate that too homely simile. Under conclusion 2 
of the Report it is said that the strength of concrete, 
apart from any reinforcement, increases as the amount 
of water used in mixing is decreased. I think the 
Committee were quite right in not building anything 
on that definition, because it is so obviously inaccurate. 
Suppose the amount of water be decreased to zero 
itself, that does not increase the strength of the con- 
crete. The limitations of the definition are glaringly 
obvious. 

With regard to Reply No. 6, a third correspondent 
says that usually about 22 per cent, of the total volume 
of cement and sand is taken for the amount of 
water. It seems strange why it should be 22. Why 
not 21 ? Why not 23? Apparently what is happening 
there is that the writer has an opinion that water to 
the extent of 15 per cent, of the volume of the cement 
and sand is required to enter into chemical com- 
bination therewith, and he has provided over and above 
that a surplus of about 50 per cent., which would bring 
it to about 22^ per cent., or, in round figures, 22 per 
cent. But there is a danger ; we speak of theoretical 
amounts. That is only part of the theory. The 
Secretary himself, and later on in the evening Mr. 
Butler, mentioned certain other factors which enter 
into the consideration of the question. Any complete 
theory takes into account every one of these. That is 
where the judgment comes in, inasmuch as judgment 
is the unconscious summing up of all the factors that 
enter into the case without our being consciously aware 
of the influence of any single factor. 

With regard to No. 23, the correspondent wishes to get 
rid of the personal element, and he suggests a method 
of doing so. That procedure has been developed in 
physics generally where, instead of the adjective "big" 
or " little " or " large " or " fair " or " middling " 
or " ordinary," they have endeavoured to get definite 
figures. That suggestion might be followed up. But 
it is not very clearly expressed. 

Then, again, correspondent 24 errs the other way. 
Instead of definiteness, he says " the consistency of 
thin cream." Well, the consistency of thin cream is 
very, very vague indeed, too vague for this Institute, 
I fear. (Laughter.) 



102 THE CONCRETE INSTITUTE 

I have tried to co-ordinate the views of all the 
correspondents and of the Committee. There seems 
generally an idea in the minds of each of them, a 
collective idea as to what the consistency should be, 
and the difference appears largely to be in the matter 
of words. Therefore I would suggest this for your 
consideration : For reinforced concrete the amount 
of water to be added should be sufficient, but not 
more than sufficient, to produce a plastic mass 
which will quiver when shaken, and exude a 
small amount of water after tamping. Now, it 
is quite possible that that definition will not suit 
a single person in this Institute, because it is an 
attempt to co-ordinate the views of most of them, if 
not all of them. (Laughter.) 

THE CHAIRMAN (Mr. WENTWORTH-SHEILDS) : 
— If no other gentleman wishes to say anything, I 
will ask Air. Yawdrey to reply. As the hour is late, 
I will only suggest one thing which perhaps he might 
have an opportunity of dealing with, and that is that this 
second sentence in this specification, which apparently 
has received the Committee's blessing, does not seem to 
me to tell you anything at all. It says that the 
quantity of water shall be such that the plastic mix- 
ture is capable of being rammed into all parts of 
the moulds and between the bars of the reinforcement. 
That rather reminds me of an old foreman to whom 
I propounded this question that we are discussing 
this evening, viz., What is the correct quantity of 
water to use in concrete ? He replied in a very 
serious and thoughtful manner, " Well, sir, the great 
thing is not to put too little and not to put too much," 
and he seemed to think that had solved the matter. 
(Laughter.) 

This question seems to me to be answered by the 
Committee in very much the same way, because one 
naturally asks in return how much water is required. 
Would it, for instance, be a wet mixture which is 
capable of being rammed into all parts of the mould, 
or would it be a dry mixture? Mr. Fraser would, I 
think, contend that his dry mixture was capable of 
being rammed into all parts of the mould, but Mr. 
Yawdrey and his Committee, I think, would deprecate 
that. It would be well to have a definition which 



TWENTY-SECOND MEETING, January ii, 1912 103 

would settle this question a little more closely. 
(Applause.) 

Mr. R. W. VAWDREY :— I think perhaps, as the 
Chairman himself has made this very direct and 
forcible attack on the Committee, I had better answer 
his question first. I can only say that I think every 
member of the Committee would be inclined to agree 
with him. The attempt to answer the question as to 
how wet the concrete should be has, of course, failed. 
That I think we must admit. The suggestion con- 
tained in the second sentence which was submitted 
in the letter to the members of the Institute was, 
at any rate, intended by the Committee to indicate the 
lines on which we wanted a reply. The answer given 
by the Committee is more or less contained in the 
clauses 1 to 6 which appear afterwards. But I en- 
tirely agree, personally, with the Chairman that it 
is impossible to say how wet or how dry a mixture 
should be in words. In my opinion, as I think I 
mentioned just now, a percentage of water does not 
indicate the degree of wetness or dryness of the 
mixture, and, therefore, my own view is that some 
sort of scale of consistency should be evolved, if 
possible, by this Institute, which would make it possible 
to refer to a particular degree of consistency of the 
concrete. 

With regard to the remarks which have been made, 
there are one or two points I should like to reply 
to. Mr. Serraillier, for instance, objected to a large 
lettering on the score of beauty and suggested stencils. 
I confess that even large lettering, which I admit 
is quite ugly, is not quite so bad as stencils. Of the 
two I prefer the lesser evil. 

Mr. By lander mentioned the question of the stan- 
dardisation of drawings, particularly as applied in the 
United States. For some reason or other, which I 
never myself have been able to understand, standard- 
isation does not seem to thrive in this country. I 
do not know why it is at all. If Mr. Bylander can, at 
any time, give me any information about that I should 
like to hear it. 

Mr. BYLANDER .— I think you are starting very 
well, Sir.* 



104 THE CONCRETE INSTITUTE 

Mr. VAWDREY :— Personally, I am trying in a 
small way to standardise things, but it does not work 
somehow or another. The scales of one quarter and 
one inch which Mr. Bylander spoke of, I think are 
more or less covered., and preferably so, by the half 
and one-and-a-half -inch scales. The great advantage 
to my mind of the one-and-a-half -inch scale is that 
an ordinary foot rule, which every foreman or most 
navvies possess, will at once enable him to read the 
drawing. The eighth of an inch mark on the foot 
rule represents an inch. That is the great advantage, 
I think. 

Then I entirely agree with Mr. Bylander about the 
importance of order lists, and the extent to which 
they will become important, and also with his remarks 
about having each drawing half the size of the larger 
one. That is, I think, very advantageous from many 
points of view, economical and otherwise. 

Mr. Fraser asked what particular drawings the Com- 
mittee were referring to. The answer is to the 
details of reinforced concrete, not general archi- 
tectural or engineering drawings, but particularly 
those drawings which are prepared for the showing 
of reinforced concrete. I entirely agree with Mr. 
Fraser's remarks about the advantage of having a 
big plan cut up into details. 

He objected to the word " plastic." The difficulty 
is to find a better one ; in fact, I noticed Mr. Fraser 
himself merely suggested another word, without men- 
tioning what. It is rather difficult to express. 

I think that Mr. Fraser would disagree with most of 
us in saying that ramming cannot be done. I think 
it can be done on fairly dry concrete which Mr. 
Fraser himself would advocate. In fact, he himself 
later on said in difficult portions of the work he 
would use a very fine concrete, which should be 
thoroughly tamped. I take it in that case he meant 
it should be fairly dry, sufficiently dry, at any rate, 
to resist the operation of tamping or ramming. The 
Committee certainly did not imply the wetter the 
better. That was not the general feeling of the 
Committee. If that appears in any way in the Report, 
it is rather regrettable ; the general feeling is that 
wetness is an evil, as I think I have remarked before, 
but that in some cases it may be a necessary one . 



TWENTY-SECOND MEETING, January ii, 1912 105 

Then, again, I think most people would agree 
that in some circumstances the mortar — that is, the 
sand and the cement — can be mixed wet and be 
poured over the aggregate. Of course it is not 
advantageous in all cases, and sometimes would lead 
to disaster, but I have seen cases in which that has 
been done with excellent effect. 

Mr. Etchells made remarks about the white versus 
blue prints. Well, everybody agrees that white prints 
are very much pleasanter to deal with, and are, I 
suppose, better for the eyes, and so forth. The only 
object that I ever heard or knew for using blue 
prints was that they were very cheap and speedy. 
Alterations can be made on blue prints. I think Mr. 
Etchells said there was great difficulty in doing that, 
but with white ink, which can easily be obtained, 
alterations can quite satisfactorily be made. But I 
entirely agree, assuming that cost is no object, that 
white prints are infinitely better. 

Then I should be very glad if Mr. Etchells would 
explain, to me, at any rate — possibly most people 
know, but I certainly do not — why, when the universal 
practice, or almost the universal practice, is to use 
the unglazed side of tracing cloth, the manufacturers 
continue to prepare the glazed side on purpose for 
it to be used ? 

Mr. Etchells suggested that by drawing the scale 
on the drawing in two directions any difficulty as 
to the drawing being true to scale in all dimensions 
and in all directions was got over ; but of course the 
recommendation in the Report is that it should never 
be necessary to rely on scaling distances, that all 
dimensions should be given. (Hear, hear.) 

Then Mr. Etchells accused the Committee of bring- 
ing table delicacies to the fore, but I would point out 
that the words " quivering like a liver " are not used 
in the Report. We just avoided that by the skin of 
our teeth. (Laughter.) 

I entirely agree with Mr. Etchells as to the use 
of the word " theoretical." Nothing appears more 
absurd to me than the way in which theory is said 
often to conflict with practice. If so, the theory is 
either incomplete or incorrect or else the practice is 
wrong. 



106 THE COXXRETE INSTITUTE 

Mr. ETCHELLS :— Might I just for a second sup- 
plement my remarks? I will not give the Hon. Secre- 
tary of the Committee anything to reply to again, 
but I hope we will each of us value our eyesight, which 
cannot be replaced at any cost, however high, above 
the slight difference in cost between blue and white 
prints. I have used white ink or common soda for 
making alterations on blue prints, but it is not so 
convenient as the black ink to be found on every desk, 
or the ever -ready blacklead pencil. 

THE CHAIRMAN (Mr. WENTWORTH-SHEILDS) : 
— Before making my final announcement, I would 
remind you that refreshments can be obtained at the 
Institute offices on the first floor of this building. 
I will conclude by telling you that the date of the 
next Ordinary General Meeting is February 8th, when 
a discussion will take place on the paper by Professor 
Beresford Pite on the " /Esthetic Treatment of Con- 
crete," which was read during the Summer Meeting 
in June last. This meeting is therefore adjourned till 
February the 8th. 

The meeting then terminated. 

The following notes have been received from Mr. 
E.G. WALKER as a contribution to the discussion : — 

Clearness and completeness of detail in the drawings 
of any engineering or constructive work are un- 
doubtedly potent factors for economy, and the cost of 
preparation of drawings forms usually a very con- 
siderable part of the standing charges of a job. In 
both these matters reinforced concrete forms no ex- 
ception to the general rule, and therefore any rational 
method whereby drawings of reinforced concrete 
structures can be standardised without affecting appre- 
ciably their general legibility is worthy of detailed 
consideration. It is obviously impossible to lay down 
absolutely hard-and-fast rules to govern every par- 
ticular in the preparation of drawings — the diverse 
nature of the objects to be delineated prevents that — 
but, at the same time, there is no reason why all 
drawings of reinforced concrete should not be prepared 
with a considerable degree of uniformity. 



TWENTY-SECOND MEETING, January ii, 1912 107 

As we in this country have not the advantages (and 
disadvantages) of a decimal system of measures, our 
ordinary working scales naturally divide themselves 
into two classes. If we start with the full-size object 
and set it out to smaller dimensions on a system of 
continual bisection, we get successively 6 in., 3 in., 
1^ in., 3/4 in., 3/8 in., and 3/16 in. to a foot. On the 
other hand, starting with the inch as our unit, we 
get 1 in., 1/2 in., 1/4 in., 1/8 in., 1/16 in., and 
1/32 in. to a foot. For large details we must use the 
first system, for an extension of the second system in 
the upward direction, giving scales of 2 in., 4 in., 
and 8 in. to a foot, is obviously inconvenient, as having 
no simple relation with the full -sized object. For 
small-scale work the universally adopted 1/4-in., 
l/8-in., and 1/16-in. scales fit in so well with the 
graduations of the ordinary rule that there can be no 
question as to the superiority over the scales of 
i/32nd, i/64th, and 1/ 128th full size. It is only 
when dealing with the intermediate sizes which are 
included in the range between i|-in. and 1/4-in. scales 
that there can be much room for difference of opinion. 
On large-scale drawings we are measuring inches 
primarily ; on small-scale drawings, feet. On the 
intermediate -scale drawings, such as are referred to 
in the Report as " elevations of beams, etc., and 
general detail drawings," the fact that such are detail 
drawings implies that the representation of inches is 
aimed at, although only as forming part of dimensions 
involving, perhaps, several feet. On such drawings, 
therefore, convenience in scaling the larger dimen- 
sions should give precedence to ease of picking out 
items involving, say, up to 20 or 30 in. It would 1 
thus appear that the scale to be used should be one on 
which, when the ordinary rule is applied, inches can 
be read off easily and to a fair degree of approxima- 
tion, leaving the accurate measure of inches and frac- 
tions thereof to the large-scale details drawn to 1^ in., 
3 in. to a foot, or even half or full size in exceptional 
cases. This consideration points to the advisability 
of a more extended use of the 3/4-in. scale (on which 
1/16 in. represents an inch). In reinforced concrete 
practice there is probably little scope for the employ- 
ment of the 3/8 -in. scale, for it is generally too 



io8 THE CONCRETE INSTITUTE 

small for the purpose of intermediate detailing, whilst 
being too large for the general drawings for which the 
1/4-in. and 1/8-in. scales amply suffice. Its field of 
usefulness is rather to be found in certain classes of 
structural and machinery drawings than as a standard 
for reinforced concrete work. But the 3 4-in. scale 
is on a different footing. In addition to the favour- 
able argument already adduced above, it also possesses 
the advantage that it is half the i|-in. scale, and this 
is a great convenience in drawing, enabling as it does 
the general detail to be made up easily from the 
particular. 

The Committee, whilst rejecting the 3 4-in. scale, 
give in their Report a very good practical reason 
for its adoption. In discussing the utility of the 
1/2-in. scale they state (p. 321) "but 1 2-in. scale 
is too small to enable details of the reinforcements to 
be shown in any but a diagrammatic way." Later 
on, dealing with the i-in. scale, they state, "but the 
1 -in. scale is often too large for detail drawings of 
long beams, and takes up much time in the drawing 
office." Surely, then, the solution of the difficulty is 
to be found by taking the middle course and using 
the 3/4-in. scale. By so doing we get a drawing 
which can be made to show as much detail as a 
1 -in. scale drawing, whilst reduced to a more con- 
venient over all size. It can be prepared at less 
cost than the i-in. drawing, and reinforcement does 
not have to be indicated diagrammatically, as the 
Committee complain is necessary on the 1 2-in. scale. 

It appears, therefore, that the general recom- 
mendations of the Committee as regards scales need 
amendment only in the particular of substituting the 
3 4-in. for the 1 2-in. scale " for elevations of beams, 
etc., and general detail drawings." 

The Committee's recommendation anent the use of 
lines of varying thickness to indicate various classes 
of reinforcement, etc. (p. 322, " Indicating the Rein- 
forcement " '), appears to be rather unpractical. Dif- 
ferent draughtsmen employ different thicknesses of 
line, and, indeed, variations of thickness are often 
to be found on the same drawing. As nowadays so 
much tracing work for the reproduction of drawings 
is done by non-technical tracers, to whom these fine 



TWENTY-SECOND MEETING, January ii, 1912 109. 

distinctions between classes of lines would not appeal, 
confusion is likely to result from the extended use 
of this convention. The substitution of the 3 4-in. 
scale for the 1/2-in. scale, to which the Committee 
propose to apply the convention, does away with the 
necessity of employing diagrammatic arrangements, 
and puts these details on the same footing as the 
larger scale details referred to in their next para- 
graph. 

The abbreviations proposed for use on drawings 
appear generally to be suitable, and in most instances 
possess the recommendation that they have already 
been found convenient in practice. The following 
criticisms suggest themselves,- however. 

The letter " b," when written on drawings, is apt 
to get confused with the figure " 6," and for this 
reason the letter " r," the initial letter of the word 
" rod," might be considered as a substitute for it. 
The importance of this point is minimised by the fact 
that succeeding symbols provide a method whereby 
the use of the symbol " b " is to a great extent 
eliminated. 

It is probably more convenient to turn the symbol 
for a channel bar through a right angle, thus [. 

The symbol □ having been already appropriated, it 
seems preferable to indicate square inch and cubic inch 
by sq. in. and cu. in. respectively, rather than by 
in 2 and in3 between the indexes of which confusion 
can easily arise. Also for indicating the Imperial 
Standard Wire Gauge there seems to be no reason 
why the more usual abbreviation S.W.G. should be 
discarded. 



Zbc Orcabam press, 

DHWIM BROTHERS, LIMITED. 
WOKING AND LONDON. 



THE CONCRETE INSTITUTE 



TWENTY-THIRD ORDINARY GENERAL 
MEETING 

Thursday, February 8, 19 12 

THE TWENTY-THIRD ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296, Vauxhall 
Bridge Road, London, SAV., on Thursday, February 8, 
191 2, at 8 p.m. 

Sir HENRY TANNER, Kt., C.B., I.S.O., 
F.R.I.B.A., F.S.I., etc. (President), in the Chair. 

The following were elected members of the 
Institute : — 

Mr. Ewart S. Andrews, B.Sc. (Eng., London), 
London. 

Mr. Percy Boulnois, M.Inst.C.E., F.R.San. I., 
etc., London. 

Mr. William E. J. Fett, Hull. 

Mr. James A. Malcolm, London. 

Mr. R. L. Nicol, Padstow, Cornwall. 

Mr. J. Vaughan Stewart, Lebu, Chile. 

Mr. George S. Roberts, London. 

Mr. David Donaldson, London. 

THE SECRETARY (Mr. H. Kempton Dyson) 
announced that Mr. Wilfred Lever, Ashton-under- 
Lyne, had been admitted as a Student of the Institute. 

THE CHAIRMAN (Sir Henry Tanner) :— We 
shall now have the great pleasure of listening to Pro- 

H 



112 



THE CONCRETE INSTITUTE 



fessor Beresford Pite again this evening, and as a 
preliminary he will read his paper again. He thought 
it would be an advantage to all those present and 
recall to them what he said on a former occasion, 
now rather a long time ago. (Applause.) 

Professor BERESFORD PITE then read the paper 
which he submitted to the Seventeenth Ordinary 



■■..■■? 



HHH9HHHHH1 





Fig. i. — Part on Left built of Granite. New part on Right built of 
Concrete in imitation of Granite. 



General Meeting of the Institute on Wednesday, 
June 7, 191 i, on "The /Esthetic Treatment of Con- 
crete," and which is printed in the TRANSACTIONS, 
Vol. III. pp. 239-51. 

PROFESSOR PITE :— Now we will have a few photo- 
graphs. 

Fig. 1. A photograph of the texture of granite on 
the left ; an imitation texture of concrete on the right. 
It sets at defiance, of course, all attempts at other 
definition. 



TWENTY-THIRD MEETING, February 8, 1912 113 

Fig. 2. A modern American building in reinforced 
concrete, an office building at Boston. It is an aesthetic 
treatment of reinforced concrete, without any doubt, 




Fig. 2. — Office Building in Boston, U.S.A., built entirely^of Concrete. 



but under the homely and natural conditions of the 
laws of stonework aesthetic . The very graceful door- 
way, of a Greek type ; the treatment of the pilasters 
and the treatment of the architrave are Greek. In so 
far as they are Greek, they are imitations in marble 



'4 



THE CONCRETE INSTITUTE 



of a wooden parentage now translated back into a 
plastic reinforced concrete, in which, of course, the 




Fig. 3. — Maison Felix Potin, Rue de Rennes, Paris. Mons. Auscher, 
Architect. 



thickness of the wall and the size of pier do not matter 
a rap. I venture to describe my doctrine as com- 
mencing, not leaving it, here. Adaptation of the 



TWENTY-THIRD MEETING, February 8, 1912 115 

recesses, of the mouldings, possibilities of projection, 
are open to us in reinforced concrete without losing the 
aesthetic values arrived at by proportions of decorative 
development and by traditional design. You can easily 
imagine, I hope, a compromise between the treatment 
of the front and the treatment of the side of this 
building. The treatment of the side is unabashed rein- 
forced concrete plus rusticated joints, for which there 
is no possible excuse other than an architectural one. 
Let us take the architecture which is lavished on the 




.,v —MR* 

Fig. 4. — Block of Flats, Savona, Italy. Mons. Martinengo, Architect. 



front and apply it thinly on the side, not being afraid 
of its thinness, recognising the fact that its thinness 
is its texture. 

Fig. 3. A house in the rue de Rennes, Paris. The 
designer has been at great pains and suffered con- 
siderable mental excitement in the endeavour to per- 
suade us that this is not stone. It is obvious that this 
is plaster. The whole of the free curves and the 
glorious bubble on the top mean the man has been in 
earnest in his attempt to teach us that this is simply 
not a stonework building. It is the struggle of these 



1 16 THE CONCRETE INSTITUTE 

building problems with artistic problems in reinforced 
concrete, but I should hesitate to call it aesthetic treat- 
ment. It does not justify itself as 'being a work of 



Fig. 5. — Mons. Francois Hennebique's Villa at Bourg-la-Reine. 

simple constructional perfection, which would, in the 
long run, justify itself without reference to any archi- 
tectural attempt. 

Fig. 4. A treatment at Savona, where the artist has 



TWENTY-THIRD MEETING, February 8, 1912 117 

felt himself conditioned, very much on the lines which 
I have suggested, by the traditions of the horizontal 
cornices, and he has been able to exaggerate projec- 
tions and recesses and even ornamental features. 
Treatment difficult to understand in stone is quite 
easy to realise in reinforced concrete, and, so far, it 
is on the right lines. It seems to lack in sense of 
refinement and restraint, because the artist has been 
struggling to express with freedom that the projec- 
tions which would not weather in stone will weather in 




Fig. 6. — Dwelling House, 40, Rue Boileau, Passy, Paris. Mons. Richard, 

Architect. 



reinforced concrete. There is an excitability in the use 
of the detail which is very troublesome to the eye 
indeed, but in so far that the building proceeds upon 
a developed exaggeration in concrete of traditional 
achievements in Renaissance palace architecture it is 
interesting. I venture to suggest humbly, in the 
absence of the author, that it just fails in the aesthetic 
quality of the architect's mind. That, of course, is a 
personal criticism which one must make with every 
apology. 

Fig. 5. M. Hennebique's own residence, designed 



n8 



THE CONCRETE INSTITUTE 



obviously as a tour de force in the construction of 
projections. I do not want to make any suggestions 
on this design aesthetically ; I leave that to the 
treasured private judgment of every one. But 
I would point out that this does express-— by way 
of advertisement — the possibilities of projection. The 
interesting flat cantilever and great cantilever beyond 
are directly an expression of reinforced concrete con- 
struction, because we could not do it in stonework or 
brickwork. We feel at once this is a novel material in 




Fig. 7. — Meeting Hall and Market Hall at Longage. 



which such projections are possible. The enormous 
soffit of the balcony, the sudden curve of the tower, the 
entire want of relation in the proportion of the open- 
ings to the piers and the weights above them — all 
are manifestly concerned with functional design. An 
arch without a buttress ; brackets without much appear- 
ance of thickness or strength or checking down. This 
is interesting. It is important, but it is not aesthetic 
treatment. 

Fig. 6. A villa at Passy, near Paris, where the 
architect has manifestly thrown away normal archi- 
tectural features, and dispensed with traditional design 



TWENTY-THIRD MEETING, February 8, 1912 119 

and Italian detail or with any would-be aesthetic style. 
He dispenses with arches and uses a pointed lintel, 
uses it only as a decoration to a panel. The window 
lintel being manifestly very thin, the supporting lines 
are obviously the constructional lines of a frame build- 
ing ; they are not the lines of a building built up on 
horizontal courses. This cantilever treatment with 
the large opening behind directly and forcibly ex- 
presses the lines of stress and design in that angle of 
the building, and there is a feeling of intense pressure 




Fig. 8. — Casino of Beausoleil at Monte Carlo. Mons. Niermans, Architect. 



and strain about these piers which the emphasis of 
the angles enables them to fulfil, just as one has no 
doubt as to the strength of a stanchion if you see it 
built up of sufficient plates and rivets. One's doubt 
is as to its being too strong, not as to its being strong 
enough. 

Fig. 7. The Market Hall at Longage is interest- 
ing because of the barrenness in the reinforced concrete 
parts and the employment of brick as a filling in the 
market hall up above, and a certain felt liberty of 
design in a quite suitable place, that is, round the 



120 



THE CONCRETE INSTITUTE 




TWENTY-THIRD MEETING, February 8, 1912 121 

clock. But the reinforced concrete tells its story quite 
directly in all this structure, and there is no attempt in 
the juxtaposition of parts to group them architecturally. 
There is no tradition of architectural proportion, but 
the design is left to work out its own salvation. A man 
must be content to say, " Here is a Philistinism ; I am 
a Philistine, and I do not care a hang about your 
artistic fancies ; I am not out to please, I am out 
to do business." This may represent a certain aspect 
of life, but it is an aspect which denies life half its 
charm and beauty and fails to satisfy. It is satisfactory 
constructionally, but standing incessantly in the middle 
of your dear old home town you would loathe it, turn 
your back on it, and would be cursing the man who, 
with all his practicability and soundness of mind, has 
bestowed an eyesore upon your home. 

Fig. 8. The scene changes to Monte Carlo, the 
interior of the Casino. We cannot describe this in any 
other way but as an attempt at aesthetic treatment. 
The curved treatment of the bracketing of the balcony 
is very easily achieved, but notice the shocking ten- 
dency to recklessness in ornamental forms owing to 
the great freedom with which the material lends itself 
to plastic modelling. 

Fig. 9. A well-known example of riotous and 
rollicking ornamental effect is the Chateau d'Eau of 
the Paris Exhibition of 1900. The whole of these 
massive ornaments, one realises, are so much wedding- 
cake ornament in plaster on a large scale. I venture to 
say that here we welcome this tour de force. It is 
a triumph, but it passes under the category of tem- 
porary buildings, and, of course, does not affect us 
permanently. We should be sick if we had to live 
with it. This was erected for a purpose which was to 
be shortly concluded and to disappear, but one notices 
the extraordinary freedom and power with which the 
French draughtsmen and designers take hold of the 
possibility of a material and give expression to it. 
The arch is admirably employed there, and it makes 
the ordinary arch treatment which would be possible 
in brick or stone to look very tame. These enormous 
aesthetic treatments just a little over -do themselves 
for any permanent design. One would get sick of 
them. But they are highly suggestive. There is a 



122 



THE CONCRETE INSTITUTE 



vast amount of matter here for the designer and the 
draughtsman. There is possibility. Obviously there 
is some ground between the Halle of Longage and 
the Chateau d'Eau of the Paris Exhibition. 

Fig. 10. Torpedo -float in the harbour at Hyeres. 
I understand it is, for the purpose of torpedo practice, 
floated out and then sunk, loaded apparently inside to 
a water-line at the sill. It interests me because of the 
Egyptian character of the outline, the sloping wall, the 
curved gorge, which are the features originally created 
by the reed and mud architecture of the Nile Valley, 



n 





Fig. io. 



-Torpedo Launching Station in Hyeres Roadstead, near Toulon, 
Var : View Afloat. Mons. de Perinelle, Engineer. 



which became sacred through an age-long history and 
were imitated in granite, the most opposite of 
materials. The designer, whether consciously or not, 
has been led into the same form. Everything that is 
massive, everything that is solid too, originally was 
everything that was thin, and thin and empty, as it is, 
of course, appears this slight reinforced concrete 
structure. 

Fig. i i. The end elevation. About its normal level 
at the water-line it is in a practising position for dis- 
charging torpedoes from the openings above and below. 

Fig. 12. Bridge at St. Claude. It is in a pic- 
turesque position, and I have no hesitation in suggest- 



TWENTY-THIRD MEETING, February 8, 1912 123 




Fig. 11.— Torpedo Launching Station for Hyeres Roadstead, near 
Toulon : View in Dry Dock before admitting Water. 




Fig. 12. — Bridge over" the Bienne at Saint-Claude, Jura. Mons. Blazin, 

Engineer. 



124 



THE CONCRETE INSTITUTE 



ing that it is a beautiful object, having the qualities 
of the material employed in a position where the mind 
is overwhelmed by natural scenery, with great restraint. 
The chief cantilever here thoroughly expresses itself. 
One does not feel that you are looking at an arch 
structure imitated in thin material. You feel at once 
that you are walking along a bracket, I was going to 
say a greasy -pole — (laughter) — till you come to the 
opposite one and are landed in safety on the other side 
of the valley. It is obviously a cantilever of concrete 








j > 



Fig. 13.— Goods Station, Newcastle-on-Tyne, for North Eastern 
Railway Company. William Bell, F.R.I.B.A., Architect. 




construction ; the overhanging footpath adds to the 
expressiveness, and the whole as an aesthetic value of 
the prime unconscious sort. It is not— and this is the 
point— an aesthetic treatment ; there is a difference. 

Fig. 13- The only English example is the great 
goods shed at Newcastle-on-Tyne, where ferro- 
concrete beams have been used in practically the 
numbers we should employ of wooden beams with the 
same result of picturesqueness. This effect lies in 
the direct serviceableness of every member, nothing 
being superfluous and nothing simply decorative. Now, 



TWENTY-THIRD MEETING, February 8, 1912 125 

success probably lies just in the perfecting of our 
architectural taste, until we are able to take something 
which has the seeds of aesthetic success and treat it 
with architectural knowledge and architectural refine- 
ment and with architectural decoration. (Applause.) 



DISCUSSION. 

Mr. A. ALBAN H. SCOTT, M.S. A., M.C.I. :— I 
do not think on this occasion we should propose a 
vote of thanks to Professor Beresford Pite for his 
paper, as this was done at the meeting at which it 
was read, but I would propose a vote of thanks to 
him for his attendance here this evening to give us 
the chance of further discussion ; and, further than 
that, I might thank him for his most excellent lecture 
on architecture as a whole, apart from the aesthetic 
treatment of reinforced concrete. 

At the previous meeting I referred to the question 
of the treatment by engineers of reinforced concrete 
from an architectural point of view, and although I 
was somewhat severely criticised, my opinion has been 
recently confirmed by the statement from a reinforced 
concrete engineer, who stated that he designed rein- 
forced concrete beams, slabs, and constructional work, 
and that the lavatory arrangements and heating and 
such like could be left to the architect. That statement 
surely shows that engineers do not understand what 
architectural treatment means, nor the duties of an 
architect, and consequently the aesthetic treatment of 
concrete. 

I would still advocate that for the present moment 
we give up all idea of applying ornament to any 
reinforced concrete work on any large scale, because 
I feel that if any attempt to apply ornament at the 
present moment is made we shall get most disastrous 
results ; and I think it is also Professor Beresford 
Pite's feeling that we should gradually grow up to 
something, and not attempt in any way to jump to any 
definite conclusion as to the proper treatment at the 
present moment. 

With this comparatively new material there are other 
problems which arise and which considerably alter the 
architectural treatment. 



126 THE CONCRETE INSTITUTE 

It is possible, and in some cases absolutely necessary, 
to get very large surfaces on the underside of the 
reinforced concrete floors without any beams whatever, 
and the only relief to the ceiling is the fan-shaped 
form of the column top ; and it seems to me that with 
the columns spreading out into a fan shape excellent 
opportunities occur here for getting good and proper 
treatment, and opens up quite a new field for treat- 
ment. 

I asked an engineer this evening if he thought it 
was possible to get successful facade treatment in rein- 
forced concrete, and he at once said " Most decidedly." 
It turns out that it is treatment of plaster jointed up 
to imitate stone. I think that is a thing which we 
must avoid, and that is one of the reasons why I advo- 
cate no ornamental work for concrete ; leave it exactly 
as it comes from the centering and only take off the 
large excrescences, and leave the work as if it is hand 
work as opposed to machine work. 

Now, I would go farther than that, and I would not 
have the concrete work faced up absolutely to a dead 
line. 

Speaking of M. Hennebique's house, I think Pro- 
fessor Beresford Pite was rather severe on that, because 
he is aware that the building was put up purely with 
a view of showing what could be done from a construc- 
tional point of view. 

I am exceedingly glad that Professor Beresford Pite 
has brought out the point about the creation of 
rusticated joints by sinking moulding fillets and his 
suggestion that it need not be even proposed. I 
would suggest that it should be very strongly opposed. 
It is coming more into use every day, both with plaster 
and also with reinforced concrete. 

Some people have an idea that concrete is an essen- 
tially coarse material, and a material which requires 
coarse treatment, but I do not agree. I should do the 
same with concrete as I should with any other cast 
material, and I should not attempt to trim off every 
little point that happens to come along. 

Would Professor Beresford Pite consider that it is 
a legitimate thing to construct the vaulting of a church 
with reinforced concrete, and apply superficial treat- 
ment such as mosaic, etc.? 



TWENTY-THIRD MEETING, February 8, 1912 127 

I propose a hearty vote of thanks to Professor Pite 
for coming here this evening, and especially for the 
slides, which were exceedingly interesting ; and I am 
sure the members of the Concrete Institute will greatly 
benefit by the paper. 

Mr. ARTHUR T. BOLTON, F.R.I.B.A. :— Mr. 
President and Gentlemen, it is very pleasant to me to 
come here this evening and listen to the paper which 
Professor Beresford Pite has just read to us. I have 
had the advantage, in addition, of previously reading 
the paper, and I should like very heartily to con- 
gratulate him on his clever treatment of an exceedingly 
difficult subject. The whole idea of how we are to deal 
with a new material is a matter which will involve a 
vast amount of thought, and the way must necessarily 
be very obscure at first. I think that probably some 
of those who are present would like to know of a little 
book on the principles of architectural design which 
is considered by many to be the best analysis of that 
very difficult subject. I refer to a little book, " Design 
in Architecture," by E. L. Garbett. It is in Weale's 
Series and cost about is. 6d. It was written about 
the time of the Gothic revival, and contains doubtless 
a good many views and statements that would seem 
absurd nowadays, but the main lines of it are remark- 
ably good. (Hear, hear.) There is a very curious 
prophecy in that book which the last slide shown to- 
night seems to show has actually been realised. After 
taking his analysis right through, very much as Pro- 
fessor Pite has done, Greek, Roman, Gothic, and 
Renaissance architecture, the author sums up the whole 
matter by saying that in Greece we had the archi- 
tecture of the post and lintel, and in Rome that of the 
arch, and that now there was no other constructive 
principle except that of the truss. It certainly seemed 
rather difficult to see in what way the truss could be 
brought into an architectural scheme, except in the 
form of roofs, which is obviously not the author's 
meaning. When, however, you visit a building like 
the Vere Street Post Office (which I had the advantage 
of going over with Mr. King, who constructed it) 
you find there trussed walls employed on a large scale. 
If I am correct in my recollection there are within the 
area of the plan of this building, which is of con- 

1 



128 THE COXXRETE INSTITUTE 

siderable size, four pillars, on to which the weight is 
conveyed by trusses, probably in depth equal to nearly 
the height of this room. The windows of the build- 
ing form in reality the openings in or interspaces of 
the truss. It is therefore a remarkable thing, you will 
agree, that Mr. Garbett in his analysis should have 
arrived at that conclusion and that we should already 
be in possession of a material which enables us to 
embody the principle of tension as exemplified in the 
truss. 

It is a question whether this reinforced concrete 
was known to the Romans or not. I suggest to our 
engineering friends here to-night to consider the roof- 
ing of the cold-water bath of the Baths of Caracalla 
at Rome. This is a gigantic hall, 170 feet long, with 
a span of about 80 feet, and ancient writers tell us 
that its flat ceiling was one of the marvels of Rome. 
The ceiling, besides being flat, had in it three or 
four large central openings for lantern lights. How 
did the Romans construct a concrete ceiling on that 
gigantic scale, flat, and with these openings in it ? 

Professor Lanciani, who has devoted a lifetime to 
the study of the antiquities of Rome, in a little book 
called " Walks about Rome," or by some similar title, 
mentions that when the cold-water bath was explored 
great quantities of T-irons were removed. The plan 
of Caracalla's Baths is in every text -book on archi- 
tecture, and our engineering friends here might see 
what they could do with that problem, and consider 
how with the aid of T-irons and concrete they would 
re -construct this wonderful feat of the Romans. 

There is not the slightest doubt that Roman con- 
struction was extraordinarily advanced ; we know 
practically little or nothing about it, but any one 
who wanders about Palatine Hill or the extensive 
grounds of Hadrian's Villa at Tivoli — and I might 
remind you that from the remains of Hadrian's Villa 
the thickness of the walls under the London Building 
Act was deduced — will come to the conclusion that the 
Romans had very little to learn on such subjects as 
brickwork and concrete. Moreover, we know that the 
roof of the Pantheon Portico, down to the time of the 
Barberini Popes, had some extraordinary trusses con- 
structed of flat plates of bronze. There is a sketch 



TWENTY-THIRD MEETING, February 8, 1912 129 

by Raphael of this metal framing, but unfortunately 
the bronze was melted up to form that monstrous 
Baldachino in St. Peter's at Rome. 

The Romans in using concrete reinforced it with 
those splendid bricks, or quarry tiles, as we should 
call them, which they habitually used. These bricks 
were either 2 ft. or 1 ft. square, and ii in. or 2 in. 
thick, and by their use they counteracted the shrink- 
age and other deficiencies of mass concrete, and also 
formed temporary or permanent casings and center- 
ings which enabled them to press on with the work. 

Of course we have by direct descent from the 
Roman times one text -book of architecture, but only, 
it is now recognised, one of a quite second-rate order, 
that is to say, the book of Vitruvius, a provincial 
architect and Imperial military engineer, who copied 
out, I imagine, from a standard War Office specifica- 
tion various building data of the period, and added 
thereto some ill -understood fragments from older 
Greek works on architecture. 

That there was some standard specification used by 
the Roman Army I hold to be true, because in every 
part of the world, wherever you go, you find the 
Roman methods are remarkably uniform. The secret 
of the Roman concrete is a thing which to me is 
absolutely mysterious. I am very familiar with the 
great Roman fortress, a mile and a half from Sandwich, 
known as Richborough Castle. This enclosure, cover- 
ing several acres, is still surrounded by a great Roman 
wall, one of the best preserved outside of Italy, and 
it was in this fortress that the Romans packed up on 
their departure from this country. The walls there 
are about 30 ft. high and 10 ft. thick, and of 
great length, but when the railways were being con- 
structed the barbarians destroyed that which faced 
towards the sea in order to use the material for the 
purpose of the railway. They began to destroy the 
return wall to this sea front by excavating a great 
cavity at the base of the wall. It is more than high 
enough to walk into and it extends 8 ft. 6 in. in 
depth, and so leaves only 18 in. of walling beyond. 
The span of that opening is about 50 ft., therefore 
you have a concrete girder say 20 ft. in depth and 
50 ft. span and 8 ft. 6 in. in thickness without the 



130 THE CONCRETE INSTITUTE 

slightest sign of a crack. It has stood since the time, 
say fifty or sixty years ago, when the cutting was 
made. In itself that is sufficiently wonderful, but 
suppose you go inside the wall and consider what it 
is constructed of. So far as one can see it is con- 
structed of nothing but the materials on the spot. 
There you see the gravel from the beach, flints from the 
chalk, and the rough class of half stone, any kind of 
inferior Kentish rag, which could be obtained near 
the spot, while the mortar binding these miscellaneous 
aggregates together appears to be made with the 
ordinary chalk or stone lime. 

What we want to know, therefore, is what did the 
Romans mix with that mortar which transformed it 
into a material as hard as our Portland cement ? 
because inside this enormous wall, 10 ft. thick, the 
setting and consequent hardness of the concrete is 
just as good as it is on the outside. That is, of 
course, contrary to all experience with ordinary lime 
mortars. 

When the Romans left this country something or 
other which had been mixed in concrete and mortar 
or some method of preparation was no longer used, 
and the Normans attempting to do buildings of the 
Roman character made a fearful mess of it. Most of 
their central towers collapsed, owing to the mortar 
being bad, as it became like sand, and the piers 
collapsed in consequence. Whether the Romans 
carried about with their armies puzzolana, or volcanic 
ash, or something equivalent to that in its effects, I 
do not know, but it is a subject I think exceedingly 
worth investigation by chemists and by societies like 
this Concrete Institute. To raise the level of the 
lime mortars, concretes, and plasters in common use 
would confer a great benefit on the building trade of 
this country, particularly in the country districts. 

Turning now to another aspect of the question, the 
finish of walls in reinforced concrete, I happened to look 
in the " Engineering Supplement " of the Times this 
week, and I saw there a paragraph about mica having 
been used in facing certain reinforced concrete tele- 
graph poles with good effect. Perhaps in granite, and 
in materials like mica, we should find a means of 
lightening up the surface of the concrete. 



TWENTY-THIRD MEETING, February 8, 1912 131 

Any one who has tried, for instance, a rough cast 
of granite and Portland cement will know how very 
much better is the effect which can be obtained — 
thanks to the nature of the granite, and particularly 
from the pink Leicestershire granite — than is available 
from the ordinary gravels or sands. There are also, 
perhaps, considerable possibilities arising from the use 
of acids in removing the excess of cement over certain 
portions of the concrete surface, and in that way 
varying its terrible monotony. 

I notice that the Professor, in his lecture, has 
omitted the Byzantine period. I think that is, in a 
way, rather a pity, because it was in Byzantine times 
that Roman architecture found itself. Byzantine build- 
ings are practically Roman constructions released from 
bondage of the Greek orders. Probably you are all 
familiar with the inside of Westminster Cathedral, a 
very notable and magnificent piece of work, where 
we seemed to have realised for us on a grand scale 
something of the feeling of a genuine brick and 
concrete architecture. 

Basing oneself on the Byzantine practice alone, I 
am afraid I cannot agree with the Professor as to 
there being any objection to their systematic finish 
by plastering, marble lining, mosaics, or otherwise, 
of both interiors and exteriors. The practice is of the 
most extraordinary antiquity, and as the question of 
shams has been raised, it is worth a few minutes' con- 
sideration. It was rather startling to me when I first 
spent some months in Italy to see at Pompeii, in 
the houses there, some of those remarkable marbled 
dadoes, in paint, that used to rejoice the hearts of the 
last generation. As an antique custom, however, this 
is nothing. We know now that the Cretans three 
thousand years ago, or perhaps more than that, did 
exactly the same thing. This practice of imitating 
materials, according to students of the earliest origins 
of mankind, began at once, and is therefore a trait 
which is so persistent that we are evidently in the 
presence of something instinctive, which requires 
accordingly a good deal of thought and reflection 
before it can be absolutely condemned. 

There is not the slightest doubt that, starting as 
they did with the ordinary mud house, finished over 



132 THE CONCRETE INSTITUTE 

to one surface, the first builders, as soon as they first 
began to build in stone, looked upon its inevitable 
joints as a defect, and that it thus became an object 
with them to obtain enormous stones, monoliths as 
far as possible. 

We are, in fact, told of such stones in the building 
of the Temple at Jerusalem, and we can see them in 
the base of the Temple of the Sun at Baalbec, the idea 
being to get walls which contained as few joints as 
possible. The system of jointing has been developed 
now, and it is a thing in which we take pleasure. On 
the idea of obtaining a surface, I do not think there 
is really anything against it that is worth considering 
from the point of view of a sham, because, after all, 
what we have to arrive at in architecture is, in some 
way or other, an effect of beauty, which, as we know. 
" doth of itself content the eyes of men without an 
orator." 

We are, of course, getting on difficult ground ; it 
is, perhaps, like truth in ordinary everyday life. I 
was once in a railway carriage where there were several 
commercial travellers, and they were discussing this 
very subject. One of these men closed the discussion 
by saying, with evident reluctance, that he was quite 
certain that a perfectly straightforward man would 
always make enemies. We know that the practice of 
speaking the truth is just as awkward in ordinary 
private life as it is in architecture and everything 
else. Certain diplomatic fictions, white lies, and other 
arrangements are used because otherwise, I suppose, 
society would fall to pieces. So it is in architecture. 
It makes one rather tired to hear people talking about 
the alleged sham dome of St. Paul's. That sort of 
talk is entirely beside the mark. There was no obliga- 
tion on Sir Christopher Wren to show us the brick 
cone inside which carries that enormous stone lantern. 
I cannot see that it was necessary for him to force 
that on our attention, any more than it is anybody's 
duty to exhibit a bony framework, or any other con- 
structive fact of a similarly ungainly character. You 
are not expected to believe that the great steeple — say, 
90 ft. high — on the dome of St. Paul's is actually 
carried by the leaded dome which you see. That 
would be an unnecessary assumption on your part. 



TWENTY-THIRD MEETING, February 8, 1912 133 

The beautiful effect of St. Paul's is justified on any 
sound system of architectural aesthetics for all time. 
I would not weary you with that except that it seems 
to me to bear on this point of the aesthetic treatment 
of these concrete structures, because I do not think it 
by any means follows that, when you have constructed 
these reinforced concrete buildings in some unusual 
way, you are absolutely compelled to force the fact upon 
everybody that you have done so. It is not the least 
bit interesting to us to see that house of M. Hennebique 
carried out in that extraordinary way. I think most 
of us would much rather he had brought out his pro- 
jections, like the old Georgian bay windows, with 
simple fiat soffits, and left us to find out how it was 
done. It is not necessary to draw anybody's atten- 
tion to the way you do the thing, so long as it is 
not shocking in itself. 

I fancy the real truth in this question of shams may 
lie in the intention, the mean motive, where it exists, 
causing the repulsion of feeling. It is quite certain 
that movements like Cistercianism and Puritanism have 
powerfully affected the development of architecture, 
but the reaction and the transformation following shows 
the partial rather than the universal truth. 

There is no doubt that reinforced concrete is, in a 
way, a new material. I think it is different to the craze 
that there was in 185 1 for iron and glass, and the idea 
that the Crystal Palace inaugurated a new era in build- 
ings. That was all nonsense and came to nothing, but 
in reinforced concrete we have something which claims 
out of two materials to make a new one. Tredgold, in 
his work on carpentry, very properly condemns the 
idea that timber structures should be made up of 
timber and iron, because, as he says, the one material 
may fail to come to the aid of the other at the critical 
moment, and that therefore the union of the two 
materials is not necessarily stronger than either of the 
two, on the principle of the weakest link in the chain. 
As I understand, however, the theory, reinforced 
concrete, and the practice or it, so far as it has gone, 
it does claim that out of concrete and steel it makes 
a new material, having qualities which are something 
more than that which the mere joint use of the two 
might imply. There is, further, the aspect of per- 



134 THE CONCRETE INSTITUTE 

manency about reinforced concrete which has not been 
given hitherto by any other steel or iron building 
material. The exact way in which reinforced concrete 
is going to be used, and how eventually it is going to 
develop, is a question that not one, two, or three 
generations are likely to solve, so far as the archi- 
tectural truth of treatment is now concerned. 

May I say with how much pleasure I have listened 
to the paper, and now support the vote of thanks to 
the reader. 

THE CHAIRMAN (Sir Henry Tanner) :— Perhaps 
an engineer will give us his views now on the subject. 

Mr. E. P. WELLS, J. P., M.C.I. :— I must object 
that concrete per se is beautiful, and I am of the 
opinion that if we want to produce anything that is 
fit to look at, there must be some kind of external 
treatment to produce a good effect. All kinds of 
means have been attempted by plastering, imitation 
stonework, etc. Now and again one sees a building 
in concrete, especially if it is in the country, that looks 
particularly well ; if it is in town where it gets the 
usual London smoke, it then in a very short time has 
the appearance of nothing but dirty stucco. 

Concrete can be made to look well if, when con- 
structed, a surface layer, as you may call it, of mortar 
about i^ in. or 2 in. in thickness is worked into it. 
That applies not only to the surface of the concrete 
itself, that is, for the plain flat surface, but also to 
any projections you may have and any mouldings you 
may put on. And if that is done, even if no lines are 
shown to represent joints, it will then give a very 
respectable appearance. If the facing is made with 
the oolites or limestones it will in a very short time 
weather and become nearly white, and will present 
almost the appearance of Portland stone ; this takes 
about two or three years. It is also easy to tool, and 
at a very low expense a very decent appearance can 
be given to a concrete surface per se, without any 
plaster work of any description being added to it. 

At the present time, as references have been made 
to silos, there is no doubt about it that in buildings 
of this description, if you put them up purely as a 
concrete structure, without any relief, you may well 
stick people's backs up at the want of architectural 



TWENTY-THIRD MEETING, February 8 1912 135 

beauty, but taking the size of such a building and 
its height, with careful treatment, with a few pro- 
jections, and with pilasters, it can be made to look 
particularly well. As far as I can judge, and from my 
experience, the thing is not to have too many vertical 
lines. You want to get a series of breaks in the 
silo, and then you will get a good appearance. But 
if you keep vertical lines from the base right up to the 
top, it then becomes intensely ugly. 

There is no reason why, when one gets into large 
structures outside of buildings, especially in bridge 
work and where you have large arches, it should not 
be jointed in the usual method so as to represent a 
stone face, because if you take a plain arch, without 
any relief of any description, you cannot say that it 
is beautiful unless you are some distance away from 
it. If there is a fog on, then the illusion is all right, 
but otherwise it is not beautiful. Still, as I say, it is 
possible to do it. There is no reason at all why, in 
the treatment of concrete, we should not adopt the 
usual architectural methods. It is an artificial stone, 
the same as you may say a brick building is artificial. 
Where natural stones cannot be obtained, as we know 
in some parts of the world — especially in America it 
is a most difficult thing to get building materials — 
why should you simply be confined to a surface to 
let the world know it is concrete pure and simple ? 
There is no reason why it should not be moulded and 
simply adapted and treated in a proper manner so 
that it is pleasing to the eye. Every time I come 
into this room I am offended by the spacing of the 
dentils on account of the irregularity in the placing of 
the beams. It is the same all round. You may take 
this room as an example of concrete, and all absolutely 
plain it would look all right. If this was a reinforced 
floor, one would only see a beam with a 4-in. pro- 
jection. One knows perfectly well that the proportion 
here is all ^wrong. The mistake made in most buildings 
is in attempting to make the beam or the column too 
small, simply to make it slender, and not take up 
so much space. Proportion all disappears, and you 
have got something which you know, if it were not 
for masking the beams in the floor, they could not 
possibly carry any of the weights put upon them. 



136 THE CONCRETE INSTITUTE 

Whether that comes into the question of the aesthetic 
treatment of concrete or not is another matter ; I am 
talking purely from the engineering point of view. 

Professor Beresford Pite, I think, is of opinion 
that the engineer should never attempt any archi- 
tectural treatment in any of the works which he 
designs. With that I do not agree at all. I think 
that now reinforced concrete has come to the fore in 
the way that it has done, a great deal will rest with 
the engineer. I believe in collaboration between the 
engineer and the architect, but when you do have an 
engineer who has also had a moderate training as an 
architect, there is no reason why he should not com- 
bine both engineering and architecture, and I think it 
will be found that, especially in the case of very large 
buildings, in the shape of factories, etc., you will get 
as good a design from the engineer as it is possible 
to get from the architect. 

One point was raised by the last speaker with regard 
to the question of the mortars that were used by the 
Romans. I think it is a well-known fact that in the 
old days the Romans simply used to slake their lime, 
generally for a period of two or three years before 
it was used, so that it became absolutely hydrated. 
There was no free lime in it whatever, and when it 
was mixed with the proper proportions of sand you 
then got a mortar that was almost equal to some 
Portland cement mortar of the present day, especially 
if they got some of the limestones slightly hydraulic 
as they did in some parts of the world. 

Another thing is this : If you take lime and make 
it into a perfect cream, and also take some ordinary 
burned ballast that is well burnt, grind the ballast 
up and then mix it with the lime, in two months it has 
set hard like Portland cement. Whether that was 
known to the Romans in the olden days of mixing 
burned ballast with their slaked lime I cannot say, but 
it is known, especially in Gibraltar and especially 
in Moorish towns, that they have a mortar there of a 
hardness that even Portland cement of the finest quality 
cannot equal at the present day. It has never been 
discovered what the composition exactly is. 

Mr. BOLTON :— Is that the material which was 
used at Tangier ? 



TWENTY-THIRD MEETING, February 8, 1912 137 

Mr. WELLS : — I believe at Tangier, Gibraltar, and 
that vicinity. 

Mr. BOLTON : — I do not know whether you know 
that in the reign of Charles II. a jetty was con- 
structed, and when Charles II. decided to abandon 
Algiers, people were sent out from England to destroy 
this jetty, and they found it a terrible business owing 
to the hardness of the mortar. 

Mr. WELLS : — It may have been ; I cannot say, 
but these works were erected in Gibraltar by the 
Moors. In some way the art of mixing mortar and 
its composition has been lost. There is no doubt that 
a lot of the mortars of the ancients were very good, 
as good as the best Portland cement mortars of the 
present day. 

Mr. Chairman, time is getting late, others may 
like to speak ; but before sitting down I must thank 
Professor Beresford Pite for his most delightful 
lecture. 

MR. E. FIANDER ETCHELLS, F.Phys.Soc, 
M.C.I. : — I have been asked to speak, but this is a 
subject that I am not at all at home in. I have 
feelings, I have opinions, but it is no good my giving 
them to you, because they are merely the echoes of 
the opinions I have heard from architects. I came 
to-night with a perfectly open mind, but after seeing 
the examples of originality I shall henceforth have 
a predilection for something classical, preferably a 
modern development of something classical. 

Reading through the paper and listening to the dis- 
cussion, it would appear that the problem to-day 
divided itself into two parts — first, whether we shall 
consider reinforced concrete as a free material having 
its own laws and its own proportions and whether it 
shall be exposed naked to the world, or whether we 
shall only deal with it as a skeleton and clothe it with 
some other material. Until the architects themselves 
have decided into what category reinforced concrete is 
to be placed, I do not propose to express any opinions 
whatsoever. Architects seem to judge entirely by their 
feelings, but feelings are the most unreliable things 
in the world, as a physicist knows, and therefore I do 
not propose to add anything to the discussion which 



138 THE CONCRETE INSTITUTE 

might be cancelled by a change of my feelings to- 
morrow morning. 

Mr. HERBERT SHEPHERD, A.R.I.B.A., M.C.I. : 
— I am sure Professor Pite's paper is one which will 
be received with every attention and consideration by 
members. It is, I take it, by such a paper as this, 
and by coming together and discussing the question 
from a strictly artistic point of view first and then 
hearing an engineer give his ideas on the matter, 
that the object of the paper is attained. It is in no 
combative spirit at all, but by genuine criticism and 
learning the different ways of viewing a new subject, 
that one is helped to a proper appreciation of the 
same. 

There are one or two points with regard to this 
which I noted down, but I feel, coming after the 
previous speakers, there is very little to be added. 
With regard to the paper, the Professor remarked 
that no artist could exist who did not tune his har- 
monies for the public approval. Well, sir, I fancy 
that the great artists more often make harmonies before 
the public understand or approve them, and it is the 
man who creates the harmony first which the public 
afterwards approve of that becomes a famous artist. 
Mr. Bolton went into an intensely interesting matter 
with regard to Roman construction in concrete, but 
I think he was rather hard on poor Vitruvius. I made 
a few notes some time ago with regard to this par- 
ticular subject, and with your permission I will refer 
to them. 

Of course, reinforced concrete is the latest material 
which the science of construction has evolved. Concrete 
reinforced with the brick or tile was one of the con- 
structional materials of the Romans, and Vitruvius Polio 
recommends it as " one of the most valuable building 
materials," so one sees it is not quite so new after 
all. That was concrete reinforced with brick or tile. 

In the House of the Vestals, at Rome, there is a 
concrete floor slab 14 in. thick of 20 ft. span ; and 
the great builders of the Byzantine period used this 
material to construct those beautiful and stupendous 
domes which have ever since been the delight and 
wonder of the world. We have in reinforced concrete 
structural steel in the new form of bars or rods of 



TWENTY-THIRD MEETING, February 8, 1912 139 

small section, distributed about and surrounded by 
concrete, the two forming a monolithic material with 
which a complete structure can be formed. 

With regard to the question of jointing, I think 
it would be quite admissible, from a constructional 
as well as an artistic standpoint, to use joints in 
reinforced concrete. When you have a large building 
you cannot do it all in a day. It does seem to me, 
and I think it was suggested at one of our previous 
meetings, that it would be a very good thing to form 
a large joint or groove where the work stopped on 
a particular day. You get up to a certain height, 
and it is surely correct, provided it was treated in an 
artistic manner, to form a large groove or joint to 
show that was a day's work. In that way, would it 
not be a legitimate constructional feature treated in 
an artistic manner ? 

Mr. WELLS : — How about when a hard frost 
came on ? 

Mr. SHEPHERD :— I don't think Mr. Wells would 
go on building at all in a hard frost. In some of the 
reinforced concrete bridges there is a simplicity of line 
that, to my mind, is extremely pleasing, the sense of 
structural efficiency that you get is quite admirable ; 
and those bridges are already giving us new forms of 
architectural expression. 

Reinforced concrete is put forward as an economical 
material, capable of being rapidly constructed, quali- 
ties which are no doubt essential to some buildings 
of to-day. But I do not think those qualities are such 
as make them essential or even suitable for architec- 
tural buildings as an architect understands that term. 
They may be for warehouses and buildings of that 
nature — I mean where rapid building is required, but 
these are not monumental buildings, and one of the 
essentials of architecture is the sense of lasting. Per- 
haps it is owing to my lack of engineering training 
that I can never see that a 2 -in. reveal looks like 
lasting as long as one of those great 6-ft. recesses 
that one sees in the Norman castles, for instance. 

Further, with regard to the application of plaster, 
I agree and think Mr. Bolton is correct in saying that 
there is no reason why you should not take reinforced 
concrete and say, " This is the structural material on 



140 THE CON'CRETE INSTITUTE 

which we wish to put a covering. We have a skin to 
cover our bones and muscles and our flesh and blood, 
and we cannot, if we would, object to it. That, I 
take it, is an example of what Nature does in a more 
or less artistic way to cover up the mechanics of our 
structures. There is no reason, so far as I can see, 
why you should not do the same thing with a building. 
It was done in the earliest example, I think, that we have 
of Greek art, the Minoan work at Knossos. The walls 
of the palace were built of unburnt brick or clay, and, 
knowing this would perish, they covered the walls 
all over with a thick coat of plaster, and on that they 
modelled figures. That is a possible suggestion for 
the aesthetic treatment of concrete, embellished with 
bas-relief, and sculpture on the lines of stucco-duro 
seems one way at least in which we might attempt 
to treat our reinforced concrete buildings. 

Mr. LUCIEN SERRIALLIER, M.C.I. :— In the 

older methods of construction, such as masonry and 
brickwork, buildings constructed in that material rely 
entirely for their stability upon the weight of the 
material of construction itself. With reinforced con- 
crete the characteristic feature is tension, and I think 
the typical form of construction in that material is 
the cantilever. That conviction has been borne upon 
me by the illustrations of M. Hennebique's house we 
have just seen on the screen. Progress will take place 
in that direction ; we shall have larger spans and great 
cantilevers, while we must necessarily somewhat modify 
our ideas of proportion. 

THE CHAIRMAN (Sir Henry Tanner) then put 
the vote of thanks, which was carried with acclamation. 

THE CHAIRMAN (Sir Henry Tanner) (address- 
ing Professor Beresford Pite) : — I have to convey to 
you the thanks of the meeting and myself for your 
very interesting lecture and for being so kind as to 
come down to us. M. Hennebique's house seems to 
be on the minds of some people. I was there two years 
ago when a deputation of the Concrete Institute went 
to Paris, and he was good enough to entertain us 
there and show us over his house. It is a very extra- 
ordinary construction, and as Mr. Scott said it was 
made principally to show the capabilities of reinforced 



TWENTY-THIRD MEETING, February 8, 1912 141 

concrete, but there is no reason whatever why he 
should not have also tried to have made it look a 
little pleasant architecturally. It is an extraordinary 
building, especially the corner tower, which was evi- 
denced by the picture shown to-night. At the same 
time it is a very useful house, very dry and very 
comfortable. He has a garden on the top, in fact, two 
series of gardens, one on the top of the tower as 
well as on the general roof, and he and his family 
spend some of their time up there, I believe, and vege- 
tables are grown and fruit trees, and they have also 
got a greenhouse. It is a very convenient house 
inside, and that is the great point, I suppose. 

Otherwise in Paris I have not seen anything that 
I should care to repeat here in the way of reinforced 
concrete architecture. Mons. Hennebique's offices in 
Paris itself are certainly nothing to copy, although 
they are quite convenient. It struck me that they 
had cost him a great deal more than if he had buik 
them under ordinary construction. I will now ask 
Professor Beresford Pite to make any remarks he 
wishes in reply. 

PROFESSOR BERESFORD PITE :— I beg to thank 
you, sir, very much for the vote of thanks. It has 
been a pleasure to have had the opportunity of dis- 
cussing this matter with you. It is quite interesting 
to find how difficult it is on artistic matters for people 
to think simply, and to believe what one says when 
one tries to speak simply. I quite despair of Mr. 
Scott. He has gone out of the room, so I cannot 
deal with him quite with that air of friendliness which, 
of course, a report does not convey. He quite 
deliberately stated what he thought was my view. 
My view, as expressed in print, is exactly contrary to 
his statement. I can just refer you to it. The paper 
is quite clear, " The only method by which definite 
progress in an architecture of concrete will be possible 
to us is by the scholarly and critical employment of 
the traditional plastic forms of architecture." Now, 
Mr. Scott seems to have been under the impression 
that that was not my opinion, but it is, and I think 
this will answer some of the interesting remarks made 
by Mr. Wells, or Mr. Shepherd, who supported the 
idea that an engineer who gives attention to architec- 



142 THE CONCRETE INSTITUTE 

ture could deal with the subject, and that it is possible 
to imagine certain principles of proportion and apply 
them to the new material irrespective of architectural 
examples in other materials. I want to say flatly, 
clearly, and plainly, it is not, and there is an end of 
it ; simply, it is not. It is not possible to imagine a 
system of proportions for a new material apart from 
those ideas of proportion which you derive from others. 

Mons. Hennebique's house proves this up to the 
hilt. You may enjoy all the consequences from this 
absence. If you depart from the accepted proportions 
which you derive from traditional architecture you 
are completely at sea. You may talk about your sur- 
face ; you may imagine that an occasional joint every 
other day or every other week during construction, 
when there is no frost, will help you, but it will not ; 
you are in the open sea. If you begin to study archi- 
tecture systematically, you will rind that the sweet little 
exercises with which you employ yourself on such huge 
works are just little exercises in ignorance. 

May I just again suggest that the point of this sub- 
ject is that the aesthetic or the architectural treatment 
of concrete buildings wants serious study, and it can 
only be undertaken by seriously laying hold of the 
principles of architecture, and that a sort of sporting 
shot at it, a sort of relying upon the average en- 
gineer's acquaintance with architecture, who does not 
wish to make a fool of himself, is not enough. You 
may take it for gospel, if you please, there are rules 
and laws easily deducible with regard to the prin- 
ciples of architectural beauty ; as easily deducible 
as the laws which I think Professor Hosking deduced 
from Hadrian's Villa at Rome as to the legal thickness 
of brick walls. We have the facts, we lay the facts 
side by side, the synthesis emerges, and when once 
you become conscious of it you find that it is a subject 
that repays study, because its principles can produce 
results when those principles are applied. 

Now, I say, apply the principles of architectural 
tradition to concrete ; the material itself will act 
through its texture upon those principles and will 
mark them for its own. You are perfectly at liberty 
to say you see no harm in marking reinforced con- 
crete in a cantilever bridge with the joints that 



TWENTY-THIRD MEETING, February 8, iora 143 

represent a stone arch construction. Do it, and be 
hanged is about all that I can say — (laughter) — but it 
is not architecture and it is not engineering, and it 
is not an aesthetic treatment of concrete architecture. 

Now, let me just beg pardon for trying to speak 
plainly, quite plainly, but let me again urge that it 
is a large subject which needs careful study. 

I am very much obliged to Mr. Bolton, in his most 
interesting and valuable speech, for reminding us of 
that little book of Garbett. Now, Garbett was a 
man who wrote before Ruskin, and as a preacher of 
sound architectural doctrine he will survive Ruskin, 
and his English is tolerable ; as good as that of an 
encyclopaedia. This little book is still on sale ; it 
is well worth attention, and will help to open eyes to 
the great interest and charm of the subject. 

Mr. Scott asked a question as to the vaulting of a 
church in reinforced concrete. Well, I have the 
drawings in my office at the present moment of 
a big cathedral in a tropical climate. I took the 
trouble to work out a reinforced concrete vault. 
You may smile at my foolishness, but I did. I 
found, of course, it ceased to be a vault ; it was 
merely putting a lid on to a box shaped like a series 
of dish-covers. There was no need for buttresses, or 
or for any features usually characteristic of such a 
building, so the problem became altogether a new 
one. I will frankly confess that I abandoned the 
reinforced concrete idea, not on that account. I fear 
my professional friends when this appears, because I 
have serious doubts as to the advisability of employing 
that material in a climate subject to extremes. That 
is the reason why I hesitate to use it in a position where 
failure would have been a very serious difficulty. Also 
the expense ; but that was not the determining factor. 

Now, we artists are difficult people to please, but 
I am going to have a crack with Mr. Bolton. He 
spoke of that monstrous Baldachino at St. Peter's 
at Rome, made out of the fiat plates of bronze from 
the roof of the Pantheon. Mr. Gilbert, the distin- 
guished sculptor, once said to me that this is the most 
beautiful thing in Christendom, so I cannot let Mr. 
Eolton call it a monstrosity without citing some other 
authority other than an architect or an engineer. 

K 



144 THE CONCRETE INSTITUTE 

As to Byzantine architecture, I do not quite follow 
the reference to its being an architecture of reinforced 
concrete — that is to say, of concrete only reinforced by 
brickwork. Am I not right in thinking that the 
Byzantine vaults are wholly of brick at S. Sophia, 
Constantinople, the structure of which is not thick 
enough, I suppose, to admit that form of construction ? 
It is possibly of a ribbed brick construction — a series 
of forty ribs from the rim to the crown. The dome 
fell three times, and was rebuilt within the century in 
its present form. In the result it is practically a 
brick -ribbed dome with brick filling. 

Perhaps I might remark that I am entirely at one 
with Mr. Shepherd as to the artist and harmonious 
tunes, but that does not issue in an attempt to evoke 
sympathy. Is not art, is not the real basis of art, 
that it is an appeal from you to others ? If you are 
going to appeal to a vacuum, you had better find your 
vacuum in some padded room. (Laughter.) It seems 
to me that is the place for it. The architect is 
especially charged to appeal to the wide public who 
walk the street, and the engineer equally because he 
is a great builder. 

And then there was one very interesting short 
remark as to the different categories of construction 
and of art, of fact and of feeling, and that feelings 
are shifty, dubious, and change to-morrow and dis- 
appear. It is not true. Venus of Milo still controls 
our feelings. The work of all the great artists has 
this in it, that their feeling is permanent. What is 
ephemeral is gone. The engineer's feelings in archi- 
tecture do go ; the architect's do not. (Applause and 
laughter.) 

The meeting then terminated. 



TWENTY -FOURTH ORDINARY GENERAL 
MEETING 

Thursday, March 14, 191 2 

THE TWENTY-FOURTH ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296, Vauxhall 
Bridge Road, London, S.W., on Thursday, March 14, 
1912, at 8 p.m., 

Mr. E. P. WELLS, J. P., M.C.I., in the Chair. 

The following were elected members of the 
Institute : — 

Mr. Victor Alden, London. 

Mr. Reginald Birkett, Manchester. 

Mr. Alfred Cordery, London. 

Mr. Alexander Thomas Cranmer, Egypt. 

Mr. Robert Gillies, Kingston, Jamaica. 

Mr. Charles Albert King, Assoc. Royal College 
of Science (Ireland), A.M.I.Mech.E., Assistant Pro- 
fessor of Engineering at Heriot-Watt College, 
Edinburgh. 

Mr. Alfred Wadsworth Lovell, Hull. 

Mr. A. C. Hughes, Wokingham, Berks, who had 
resigned in November, 191 1, was reinstated as a 
member. 

THE SECRETARY (Mr. H. Kempton Dyson) 
announced that Mr. Frederick Joseph Findon, of 
London, had been admitted as a Student of the 
Institute. 

Mr. REGINALD RYVES, Assoc. M. Inst. C.E., 
M.C.I., then read his paper on " High Dams of Great 
Length " as follows : — 



146 THE CONCRETE INSTITUTE 

HIGH DAMS OF GREAT LENGTH. 

THE MASS GRAVITY TYPE AND THREE 
TYPES OF SPAN DAMS. 

By REGINALD RYVES, Assoc.M.Inst.C.E., M.C.I. 

WHEN an engineer undertakes a special study of any 
kind, he usually finds that certain considerations v : tally 
affecting the problem before him have not received 
quite as much attention as their importance demands, 
and he sometimes finds, too, a new path of study, or 
investigation, or some new way of applying well- 
established principles. In both cases he may gain 
much by putting his views before his fellows, and 
their opinions and criticisms will help to put these 
matters in the true perspective, to confirm or correct 
his opinion as regards what he thinks has been neg- 
lected or not fully grasped, and to point out where 
his new path has already been well trodden or where 
it leads to an impassable chasm. 

The special study which the author of this paper 
undertook, and on the results of which this paper is 
based, was a study of high masonry dams of such 
length that they may be regarded as dams proper, 
and in no sense as structures partly held up to their 
work by the sides of the river valleys. While the great 
size of the two dams contemplated rendered economy 
of material an important matter, this was absolutely 
dominated by the still more important consideration 
that the dams must be in all respects stable and lasting. 
It was also desired to avoid as far as possible the 
use of Portland cement. 

Leaving aside all other considerations arising out 
of the study, this paper is confined to those connected 
with the building of dams of a great length, the 
whole of which length is more than 140 ft. clear of 
the ground, and a part of which may be as much as 
180 ft. or more to hard rock. The height of 185 ft. 
clear was adopted for purposes of calculation. The 
subject of the paper is, further, kept within some- 
what close limits by the condition that the highest 
calculated maximum stress in the masonry must not 
exceed 1 2 tons per square foot, at any rate by 



TWENTY-FOURTH MEETING, March 14. 1912 147 




J48 



THE CONCRETE INSTITUTE 



« 09 



\l 



se-* 



TWENTY-FOURTH MEETING, March 14, 1912 149 

Bouvier's computation, though by Unwin's computation 
a somewhat more severe stress may be allowed. 

Before setting forth the definite propositions which,, 
it is hoped, may concentrate discussion, it may be well 
to point out that there are four distinct types of dams 
for wide valleys, and entirely excluding the dam which 
is a single arch, in plan, and the dam which is, in 



Section A B 

+200 



CROSS 
WAUL 




Fig. 3.— Thrust Buttress Dam. 

its lower part, practically a plug in a gorge. The 
four types are : — 

1 . The mass dam proper, designed on the ordinary 
theory. 

2. The parallel slice dam, which is designed in 
exactly the same way, but with more concentrated 
water loads. 

3. Captain Garrett's type, or the dam of arches in 



150 THE CONCRETE INSTITUTE 

which the weight of the arches is partly taken into 
account, but the dam otherwise designed as a gravity 
dam with concentrated water loads. 

4. The author's proposed thrust buttress dam of 
arches, in which the whole of the water load is taken 
by masonry in direct compression, and neither the 
weight of the buttress nor the weight of the arch is 
taken into account as regards stability, except for 
resistance to sliding bodily when the ground is com- 
paratively soft. 

As regards the first class, the mass gravity dam, 
we find that for high dams, above 150 ft., the 
maximum stress increases very rapidly indeed, and 
that to build a dam 200 ft. high we must exceed a 
stress of 1 2 tons per square foot by Bouvier's com- 
putation, and greatly exceed it by Unwin's computation. 

For a dam 185 ft. high, and where a is the angle of 
the resultant with the vertical and <p the angle of the 
masonry face at the toe with the vertical, we get, in 
a normal design, with masonry of specific gravity 2j, 
and with p (calculated by the usual rule; as followed 
by Wegmann and others, such figures as — 

p = 7 85 tons per square foot 
p sec 2 a = 10-92 ,, 
p X sec 2 <p — 1790 ,, 

Higher stresses than 12 tons per square foot by 
Bouvier's computation have been allowed underground, 
but there is no precedent for a long, straight dam 
which is considerably over 150 ft. clear of the ground 
for any considerable length. 

Coming now to the second class, which is one type 
of the dam of spans, and may be a good type to build 
when it is necessary to leave ample waterway during 
the building, we find that its height is limited by two 
considerations. First, we cannot bu ; ld truly parallel 
slices of more than some limiting height without side 
buttresses. If we slope the sides the strict theory no 
longer holds good, and we shall find that we arc 
logically led to Captain Garrett's type, in which the 
weight of the arches is partly counted upon for 
stability. The other limiting factor is that the con- 
centration of water loads in these separated slices in- 
creases both a and so much that we get very high 



TWENTY-FOURTH MEETING, March 14, 1912 151 




4748 v 5786**.664$ S .75I8 > V 
— _ _x *;, _. _>„ ,J 



Fig. 4.— A Parallel Slice Dam : Gravity Buttress. 
■1-185 WATER LEVEL 



Stress : 

P = 7-85 tons/ft. 2 . 

P x sec. 2 a = io - 92 tons ft. 2 . 
P x sec 2 = 17-90 tons/ft. 2 . 



+ 




MAX STRESS 
O65.TOMS PER 



Fig. 5. — A Mass Dam. 



152 THE CONCRETE INSTITUTE 

maximum stresses. Thus, for a dam $ solid 
and f span, the calculation being made as 1 for a 
mass dam for a liquid with specific gravity 3, we 
get, for a height of 162^ ft. and specific gravity of 
masonry 2\ — 

p = 472 tons per square foot 
p x sec 2 a = 9'io ,, ,, 

p x sec 2 = 25-39 ii 

Although, as Professor Unwin has pointed out, we 
need not believe that such a high stress as the last 
noted actually exists, we are obliged to take the theory 
into account in comparing one dam with another, at 
any rate until some one can give us a modification 
for very flat angles. 

It is clear that though this type may be very 
economical for heights up to 100 ft., and may be used 
up to 150 ft., if we are not afraid of sec 2 <p, and build 
it half gaps and half slices — gaps and slices of equal 
length along the dam — it does not help us in designing 
a very high dam. 

It may be noted that with a dam half gaps, the 
specific gravity of the liquid of calculation being 2, 
we get, for a dam 162^ ft. high and specific gravity 
of masonry 2.\ — 

p = 5*43 tons per square foot 
p x sec 2 a = 8-91 ,, „ 

P x sec 2 <p — 18*29 11 •• 

If we can adopt some method of combining the 
use of p sec 2 a with that of p sec 2 <j> , we might build 
such a dam. 

Since the weight of the water apron is not taken 
into account at all in this type, it is one which is 
adapted for use with thin arches of very strong stone, 
or a ferro -concrete beam and slab arrangement, for 
the water apron. 

The third type, in which the weight of the arches 
is partly taken into account, has been successfully 
used for the Agar dam, in Rajputana, a dam 68 ft. 
high, designed and built by Captain A. ft". Garrett, 
R.E. 

The indeterminate nature of the stresses is, how- 
ever, against this type for great heights, but with 



TWENTY-FOURTH MEETING, March 14, 1912 153 



SECTION 
ARCH RINC 




SECTION 
THROUGH PIER 



Fig. 6.— Garrett's Design for a 150-ft. Dam. 



Stress: 
P = 472 tons/ft. 2 . 

P x sec. 2 a = 9" 10 tons/ft. 2 . 
P x sec. 2 <£ = 25-39 tons/ft. 2 
Specific gravity of masonry i\. 




$-64+° 



MAX. STRESS -9-2 TONS O" 

Fig. 7.— A Parallel Slice Dam, \ solid, § gap. 



154 T HE CONCRETE INSTITUTE 

small gaps and large buttresses it has certain advan- 
tages. For instance, with the bases of the buttresses 
merging together it would be a very good type for 
through-sluices, or for a suitably arranged overflow. 

Captain Garrett has made a design for such a dam 
150 ft. high, and the question whether it may be 
built up to heights of 200 ft. above-ground may, 
perhaps, be left to his initiative. 

For a height of 100 ft., a comparison of costs shows 
that under certain conditions the advantages of clear 
openings totalling f the length, and of more definitely 
calculated stresses, could be attained by building a 
parallel slice dam at an additional cost of 20 per 
cent, compared with Captain Garrett's type. 

We now come to the fourth class, the author's 
typical design for a thrust buttress dam. The best 
slope for the water face is, under normal conditions, 
45°, and the dam then consists of inclined arches, of 
increasing thickness with increasing depth sloping at 
45°, the abutments resting against the up-stream face 
of the buttresses, which are built up of layers all 
inclined at 45 , the thickness depending upon the 
material used, and the width of each layer being such 
that the thrust upon it is the maximum allowed thrust. 

The calculation of thrust is made by adding the 
water load transmitted to any plane parallel to the face 
to the resolved part of the weight of masonry above 
the plane in question, the same method of calculation 
being adopted in every part of the buttress. The 
resolved part of the weight of the arch is, in each 
case, added to the water load. The water loads are 
thus transmitted by direct thrust, the layers not being 
bonded together, but left free to take up the deforma- 
tion under the water load by sliding on one another. 
If the rock will not take the load at an angle of 45 , 
the water face may be made flatter and longer, and 
the buttresses, always at right angles to it, steeper 
and shorter. The typical design is, however, that with 
a 45 ,J slope. Every part of the dam is subject to the 
same stress except that the top layer of the buttress 
and the upper part of the arch ring may have, respec- 
tively a greater width and a greater thickness, the 
minimum in each case for the materials used. 

This adoption of a general stress, instead of one 



TWENTY-FOURTH MEETING, March 14, 191 2 155 

varying from nearly zero to some maximum, is an 
important element of economy. 

Comparing this dam with a mass dam, under certam 
conditions of site and costs of material, the following, 
for dams 162^ ft. high, was found : — 

Mass dam, maximum pressure (Bouvier) 10 tons \ Masonry, 
per square foot. ) 100 units. 



Th 



rust buttress dam, minimum arch thickness 6 ] 
feet, stress in arches 15 tons per square foot, / 
in the buttresses 10 tons per square foot. J 



95 units. 



Thrust buttress dam with a minimum arch / .; 

thickness of 4 feet. I y ~ 

The difference would be considerably greater if we 
made, for the mass dam, p sec 2 <p = 10, or even 
p sec 2 (f> — 12. 

If the rock is not strong enough to take as high 
a maximum stress as that allowed in the buttresses, 
the layers can be footed out to a greater width below 
ground-level, subject to a limitation by the height 
and the allowable stress, upon which depends the 
amount of spare distance between the buttresses. 
Similarly, even if the rock may be subjected to a 
stress as high as that in the buttresses, there is, for 
each stress allowed, a limiting height, which brings 
the buttresses together at their bases. With a stress 
of 10 tons per square foot the height is a little over 
200 ft., and with a stress of 16 tons per square foot, 
about 300 feet. 

Such a dam may be built of materials which are 
not suitable for the rubble masonry or mass concrete 
of a mass gravity dam. For instance, slabs of lime- 
stone or hard shale may be used, both in the arches 
and in the buttresses, with their beddmg planes at 
right angles to the direction of thrust, or it may be 
built with blocks of concrete. On the other hand, it 
can be built of rubble masonry, or the layers can be 
built up from their lower cuds, of rammed concrete 
between rubble walls. 

On the whole, there is greater choice of materials 
than in the building of a mass dam, greater choice of 



156 THE CONCRETE INSTITUTE 




Fig. 8.— New Croton Dam. 




Fig. 9.— Chartrain Dam (Masonry weighs 150 lbs. per cu. ft.). 



TWENTY-FOURTH MEETING, March 14, 1912 157 

methods, and, as in the case of any dam of spans, 
fewer difficulties in the management of the river and 
hardly any trouble from expansion or contraction. 

The definite propositions which the author puts 
forward are : — ■ 

1 . That there is no precedent for the building of 
a mass gravity dam in an unassisted length more than 
150 ft. clear of the ground. 

2. That our present ideas as to maximum stresses 
allow of the building of such a dam for heights only 
slightly in excess of this. 

3. That since the improbability of the stress actually 
reaching p sec 2 <p increases as the slope at the down- 
stream toe is flattened, we may, for heights above 
150 ft. and for angles flatter than 45°, allow one 
maximum computed stress for p sec 2 o, and a com- 
puted stress for p sec 2 </>, some 50 per cent, higher. 
This applies both to mass gravity dams and to parallel 
slice gravity dams, and perhaps also to Captain 
Garrett's battered buttress type. 

4. That interrupted dams, the gaps being spanned 
by horizontal or inclined arches, or by beams, offer 
the important advantages — 

(a) Economy of material ; 

(b) Absence of contraction cracks and tempera- 

ture stresses ; 

(c) Maintenance of waterway during construc- 

tion ; 

(d) Cheapness of sluices ; 

\e) In some cases a wider choice of materials 

and of methods of building ; 
(/) And that the interrupted dam, or dam of 
spans, may be considered as an alternative 
to the mass gravity dam for great heights,, 
especially as regards the height clear of 
the ground. 

5. That the author's design for a thrust buttress 
dam is suitable for heights up to 200 ft., with materials 
allowing of a compression stress of 10 tons per square 
foot and up to 300 ft., if a stress of about 16 tons, 
per square foot be allowable. 

6. That none of the dams at present built are thrust 



k8 



THE CONCRETE INSTITUTE 




Fig. io. — Proposed Typical Foundation for a High Dam. 
R.WL. 



CRAVED 




SILT..;-.^.. 



|B_J_ 

Fig. ii. 



TWENTY-FOURTH MEETING, March 14, 191 2 159 

buttress dams, either as regards the method of building 
or in practical effect. 

7. That in order to avoid tension near the up- 
stream toe of a high mass dam, or of a gravity 
buttress in a dam of spans, it is desirable to make 
the connection with the rock somewhat as follows : — 

The upstream third of the base a fiat surface with 
no bonding and no trench; 

The middle third bonded, but not deeply trenched ; 

The downstream third effectively bonded with the 
rock cut in faces at right angles to the thrusts of 
the masonry. 

TABLE I. 

Dams 162^ Feet High. 



Comparison of Parallel Slice Dam (Mr. Rvves) with a Mass Dam, the 
h eight being i6£ ft. 

The specific gravity of the masonry a\ in every case. Maximum 
stress allowed, 10 tons per square foot in the buttress and 15 
tons per square foot in arches. 



Type of Dam. 


°-c 


Archwork 
for 1 R.Ft. 


Piers with 
Buttress 
Masonry 

for 1 R.Ft. 


Total for 
1 R.Ft. 


Percentage. 


Mass Dam ... 


I 


— 


— 


9,453 


IOO 


Parallel Slice Dam... 


2 


626 


7,49 1 


8,117 


85-9 


Do. 


3 


I,o8o 


6,834 


7,916 


837 



8. That when a high dam is to be built with a 
large part of its total height from foundations below 
the bed of the reservoir, it may be worth while to 
relieve that part of the upstream face from water 
load by directly draining it through the dam. 

9. That dams in the tropics, or near the trojpics, 
with downstream faces towards the Equator, or facing 
east or west, may with advantage be provided with 
temperature skins to a depth depending on the extent 
to which daily or annual changes in temperature 
deprive the outer shell of the face of its value as 
material resisting compressive stress. 



6 = 



'2—3 

•^ r. o 






r- ■*. O 



E'S 






Q 





S. 

zc 




b2 

b r. 

|o 

J 


P m Ss c »■ D « « r 

Si*- Sb- Sbv 
II II II II 


H 

s. 

O 

u 

X 

5 

o 
■/. 

7. 


Allowed pressure in arches = 20 tonssq, ft, 
No allowance is made for changes In 

temperature in arch rings. 
Rale for buttress masonry =R per 100 cu ft. 
Rate for archwork ,, R per 100 ,. 
Rate for excavation ,, =R per 1,000 ,, 


I 

5 

c 
■- 


z 

/ 
z 

- 

V. 

z 



I'i. 1 ° 1 J g 


1 S f f. 


3 2 
U 


e~ -1 i^ 

■c ' "-. -r 1 "•• 
b b b 


'{■ C — :s i: 2: 
1 1 1 <£■ 1 "2 1 SI 3 


Zl X ' 

go 1 ! .j 


■J 

< 

\ 

6 

o 

Z 

g 

7. ' 


Allowed pressure in arches^ zotonssq 11 
Extra tliickncss allowed for temperature 

changes in arches t ft, 
Rate for buttress masonry =R per 100 cu. 1 1 
Rate for archwork „ =R per 100 „ 
Rate for excavation ,, =R per 1,000 „ 


X. 
X 
X 


u — 

- "— i 
- ox r> t-» 

'J 




sj I- a - % 1 

.5 b b b 


u S t>. 00 1 r> »n 1 

ZZ .; ^ r ' -* 3 " .^ ' 
3 r: tn rr b x 


u 


ai 1 5 1 a 1 s 1 

< 3 -^ io b 


7. 

■3 

z 

< 

u 

g 
z 
7 


Allowed pressure in arches* 15tonssq.fl. 
Extra thickness allowed for temperature 

changes in arches = ij ft. 
Rate of buttress masonry=R per 100 cu. ft, 
Rate oi archwork 3/2 K per 100 cu. ft. 
Rati of excavation R per 1,000 cu. ft. 


< 

- 



z 

•_■ 
z 
z 
x 

:j 

"x. 

Z 


S a ° '- * " 


>*■ 1 <3 1 >n 

H zr b. ° -^ 


" ZL — ZZ ZC 
- = t^ m 1 t~ 1 -1 
.5 — 00 b b 




JG% I » I « | » j 


•asvg iv a:<id jo moxaq £. £ £ £ .£ £ £ 


•dox xv aaij jo Hioxai „ £. £. b o -r - 


•aaij ao sshnhsihx i 1 3 ° ° - ° 2 


ai 


•xoixvukvivc 

.idl'I JO AXIAVa 


) H3d 
3UI 


?HdS 


j 



TWENTY- FOURTH MEETING, March 14, 1912 161 

10. That a long and high mass dam may usually 
be, with advantage, built with gaps in the masonry 
across the length, these gaps being filled when the 
temperature of the dam is judged to be nearly at 
or a little below its future mean temperature. If 
cracks are specially to be guarded against, the gaps 
may be filled at the end of the cool season and after 
the temperature of setting has subsided — that is, when 
the average temperature of the masonry is at its lowest. 

1 1 . That the grading of material in a large dam 
should be such that the large stones are not " plums 
or displacers, but play the part of the stone in ordinary 
concrete. 

The general theory of arched dams is explained, 
and Captain Garrett's type described, in Professional 
Paper of the Royal Engineers. Fourth Series, Vol. II., 
Paper No. 1. By Captain A. ff. Garrett, R.E. 

The author's studies are fully reported in a " Note 
on Mass Dams and Dams of Arches," a Madras 
Government paper, P.W.D. (Irrigation). 

The author's statement of the general problem and 
a concise description of his type design for a thrust 
buttress dam will be found in the Engineer, Feb- 
ruary 24 and March 3, 191 1— 'The Problem of the 
High Masonry Dam." 



DISCUSSION, 

Mr. CHARLES F. MARSH, M. Inst. C.E., M.C.I. :- 
Mr. Chairman and Gentlemen, I think Mr. Ryves is 
to be very much thanked, I will not say congratulated, 
for bringing to this Institute a paper of this nature. 
It is a very high-class paper, and although we are 
accustomed to very high-class papers, still I must 
say that I think this paper is one of the best which 
we have ever had before us. 

I should like to ask the author — I am not up in 
Indian engineering — about the parallel sliced dam. 
Am I to understand that it is formed of buttresses 
with parallel sides in contradistinction to ones with 
wedged -shaped buttresses, and that therefore the arches 
are of the same span all the way down ? I do not 
quite understand how the arches of the parallel sliced 
dam abut on to the slices. 



162 THE CONCRETE INSTITUTE 

With regard to the height of high masonry dams, 
I do not quite understand Mr. Ryves and think he must 
have made some mistake. In the case of the New 
Croton Dam, for instance, the author has stated 238 ft. 
as the height. Only yesterday I was reading the 
Proceedings of the American Society of Engineers, 
and it was stated there, distinctly, that the New Croton 
Earn was 297 ft. high from its foundations. I pre- 
sume that the height given by Mr. Ryves is the sort 
of average height throughout the high portion of the 
dam. The new Olive Bridge Dam is a dam of the 
considerable height of 252 ft., and I believe it is a 
dam of considerable length, and I daresay the 252 ft. 
extends for a considerable portion of the length. 

The reason I bring this forward is that I understood 
from the paper that the author seemed to imply that 
an ordinary mass dam, 200 ft. in height, was almost 
impossible for any considerable length. 

The form of dam which the author advocates is, of 
course, new — it is new to me, at any rate — and it 
appears to be an extremely good form of dam and an 
extremely economical one. It calls to my mind, of course, 
the section of the reinforced concrete dam. Personally, 
I have never seen anything in the nature of a masonry 
dam, using masonry in its larger sense, of anything 
like this form. His dam is like the reinforced con- 
crete dam of the ordinary type in that it has a water 
face with slopes of 1 to 1 or even flatter, supported 
by buttresses, although the buttresses are very wide 
at the foundations. It has the advantage which the 
reinforced concrete dam possesses, that if there is 
considerable leakage past the front toe the pressure 
can be relieved from acting on the foundations by 
letting the water flow freely through them. This 
relief cannot be so efficient in the case of Mr. Ryves's 
dam as in the case of a reinforced concrete dam since 
his buttresses extend over a considerable portion of 
the foundation. 

The author stated that a reinforced concrete dam 
could not be built to any considerable height. I 
have not gone into the question at all— I daresay he has 
—but I should rather like him, if he would, to state 
the limits to which the ordinary type of reinforced 
concrete dam with a slab and' buttresses could be 



TWENTY-FOURTH MEETING, March 14, 1912 163 

built. The great advantage of a reinforced concrete 
dam, or one of the great advantages, is this, that there 
is absolutely no pressure on the outer side of the upper 
stream face, because if you have a wall along the toe 
down to the impervious strata, any upward pressure 
is relieved at once by letting it drain through the 
base of the dam and so down stream. Another 
advantage is that the pressure on the foundations is 
more evenly distributed than in the case of a gravity- 
dam . The pressure distribution diagram is not in 
the form of a triangle, it is almost in the form of a 
rectangle, and approaches the rectangle more nearly 
as the depth of water increases. In the case of Mr. 
Ryves's dam, a similar distribution of pressures occurs 
at the buttresses. I have been working out some 
calculations with respect to the vertical component of 
the pressures under the apex of Mr. Ryves's dam, but 
I made a mistake at the beginning, so they are not 
much good. Has the author taken into account the 
vertical component of the pressures on this dam. What 
I mean is, that according to the height of the dam 
there will be a certain weight of masonry underneath 
the apex which will be distributed over the full width 
of the buttresses, and there will also be a considerable 
pressure due to the water on an inclined face of 
1 to 1 . Although the vertical components of the 
pressure at the base are more evenly distributed by 
there being a flatter slope on the water face, they 
are also greatly increased. I do not know whether 
he has ever taken out— I suppose he has— the vertical 
pressure which he would get directly under the apex 
of the dam with reservoir full. There are one or 
two things I should rather like to know. One is as 
to the draining of the upstream face below the bed 
of the river or the surface of the ground. Of course 
in India I do not know what the conditions are, and 
you may get a waterproof sealing of the surface of 
the ground very soon, but in England it would, of 
course, be an extremely dangerous thing to put drains 
through at the bottom of a masonry dam, it would 
probably empty your reservoir. I suppose that would 
not occur in India. 

I also do not quite understand what 'he meant about 
" plums." I have always thought that the great thing 



i6_| THE CONCRETE INSTITUTE 

to be aimed at when you are putting in big blocks 
of stone in concrete as ' piums " was to keep them 
apart, and properly surround them with the ordinary 
concrete, the concrete being mixed in the proper pro- 
portions, to prevent leakage of water. It is extremely 
economical to put in large blocks of stone and the 
concrete is none the worse for it, but I should have 
thought that these stones should certainly be kept 
from four to six inches apart at the least. 

Once more I should like to thank the author very 
much indeed for his exceedingly able paper. 

Mr. EWART S. ANDREWS, B.Sc. (Lond.), 
M.C.I. : — Mr. Chairman and Gentlemen, I am in the 
happy position, or unhappy position perhaps, of never 
having had the privilege before of listening to a paper 
read before the Concrete Institute. I am unable, 
therefore, to compare its merits with those of its 
predecessors, but this paper does appeal to me as being 
a most valuable one, and one upon which I, for one, 
would like to obtain some further information. My 
own knowledge on the subject of dams is restricted 
to the theoretical consideration of the case. I have 
had no experience of the practical construction of 
them, but I had the good fortune of being at University 
College some eight years ago, working with Professor 
Pearson at the time that he was working with Mr. 
Atcherly on the subject of the stability of dams, and, 
as you are probably aware, the result of his investiga- 
tion was a paper which raised a very large amount of 
discussion amongst those interested in the construction 
of dams. For that reason I have always taken a 
considerable interest in the theoretical aspect of the 
problem, and it has always seemed to me that the 
stability of dams is, from a theoretical point of view, 
one of the most troublesome problems which the 
structural engineer has to consider. 

The whole of the ordinary theory of dams is based 
upon an assumption that the masonry is an elastic 
material, which assumption is probably considerably 
far from the truth. As far as I know, nearly all 
the dams that have been designed have been based 
upon the well-known law of the Middle -third, and it 
has always seemed to me to be a very happy accident 
if it happens to agree with the result in practice, and 



TWENTY-FOURTH MEETING, March 14, 1912 165 

it is on account of the extreme difficulty of the satis- 
factory theoretical treatment of the ordinary gravity 
dam that it seems to me that we want to be 
rather careful how we approach the subject. 

I notice that the author has made comparative 
calculations with the Bouvier and Unwin theories. I 
should like to know his opinion of the Bouvier and 
Unwin theories. Perhaps he would not mind explain- 
ing to us how they are obtained. I think I under- 
stand, but they seem to me to be based upon a 
fallacy. At any rate, I would like to have some 
further information as to this point. 

I am rather surprised that some reference has not 
been given to the consideration of the stresses in dams, 
based upon the points which were raised by Professor 
Pearson in the paper to which I have referred. That 
paper was intended principally to direct attention to 
the tensile stress in the toe of the dam, caused by the 
upward pressures acting upon the toe as a cantilever, 
and thus causing the tensile stress in that way. Later 
on Professor Pearson carried out some further experi- 
ments on jelly models of dams, and although he 
found very great difficulty in getting results that were 
sufficiently consistent to enable him to enunciate any 
scientific theory, his result was, that one of the most 
important points to allow for was the bonding of 
the dam to its substratum, not on the side shown in 
Fig. 10, but on the opposite side. I would like 
the author to say whether he considers Professor 
Pearson's investigations insufficient in that respect. 

Now, coming to the particular form of dam for 
which the author is responsible, I must say that 
although I had the opportunity of reading the paper 
referred to, I was unable to give it the attention which 
the matter deserves, and I think that many other 
members would like to have some further explanation 
of the manner in which the stresses are calculated 
in this form of dam. I think the author, perhaps, 
has made the mistake of imagining that all of us 
know as much about the subject as he does ; and I 
am very sure we should very much appreciate some 
further explanation in that direction. I think, sir, 
those are all the remarks I have to make. I would 
like to add my thanks to those of the previous speaker 
for this very interesting paper. 



1 66 THE CONCRETE INSTITUTE 

Mr. E. FIANDER ETCHELLS, F.Phys.Soc, 
M.Math.A., A.M.I .Mech.E., M.C.I. :— Mr. President 
and Gentlemen, I should like to support Mr. Andrews 
in asking for the derivation of the formulae. It is 
quite apparent from the paper that Mr. Ryves has 
given more attention to the question of high dams 
than most of us. We, in London here, have access 
to our libraries and our text -books in which the data 
are given and can verify the formulae and their 
derivation, but I would like to ask that an appendix 
be added to the paper showing clearly how the formulae 
are obtained, for the sake of those of our members 
who are out on the " frontiers of Empire " building 
dams, with perhaps but a few old text -books by them. 
I think that the data would be of great assistance 
to them, and the auth.or has all the information at his 
disposal, so it would not be trespassing too much upon 
his time. 

The author deprecated putting a trench in front 
of dams. It is presumed that the principal objection 
to the front trench is that there is, or may be, a ten- 
dency to form a vertical crack extending upwards 
from the back of the trench. 

The author stated that dams in the tropics, or near 
the tropics, with downstream faces towards the Equator 
or facing west or east may with advantage be pro- 
vided with temperature skins to a depth depending 
upon the extent to which daily or annual changes in 
temperature deprive the outer shell of the face of its 
value as material resisting compressive stress. It is 
presumed that the extra skin should be on the down- 
stream face 

Mr. RYYES : — Downstream face, I say. 

Mr. ETCHELLS :— The point is an important one, 
and it is necessary to discover under what conditions 
we are to use the temperature skins. While for the 
moment, it appears as though we are dealing with 
some subject outside reinforced concrete, the questions 
to be raised have a very direct and practical bearing 
on the actual construction of the dam. It is really 
important, so that the engineers I have spoken of, 
that are far away, may know when they should and 
when they should not put on the temperature skins. 



TWENTY-FOURTH MEETING, March 14, 1912 



16' 



Rather than enter upon a long astronomical dis- 
quisition on the aspect of the sun in various latitudes, 
I submit herewith two diagrams showing that it may 
be necessary to construct temperature skins on dams 
which have an aspect contrary to that indicated by 
the author, in addition to those cases which the author 
has specially mentioned. 

In regard to Garrett's design, there is one point in 
Garrett's design which I should like to draw your 
attention to, because it is not always attended to in the 
arched dams. You will notice that Garrett has his 
arches at the arc of a circle. That, I should think. 




6* 

Summer Solstice 



Winjter Solstice 



Diagram showing that the necessity for o temperature skin 
exists whether the downstream foce is towards the Equator or not 



would be quite correct, because the pressure of the 
water is radial in every direction, and if you could 
complete the arch you would get a circle of radial 
pressures, and Garrett's design on that point is cer- 
tainly a good one. 

I would like to ask the author for information as 
to the horizontal reactions. In the case of the very 
high dams, often considerations come in that may 
be fairly negligible in a little retaining wall round 
a building. The question is as to whether the whole 
of the horizontal reaction is assumed to be taken up by 
friction or whether partly by friction under the base and 
partly by shear of the toe. In other words, does the 
author, in his practice in very high dams, take the 
question of friction along the bottom as being the 



168 THE CONXRETE INSTITUTE 

sole determining factor, or does he take the shear 
stress across the toe as being auxiliary and not 
supplementary ? He takes a combination of both, I 
presume. 

Mr. RYYES :— A combination in the middle ; a 
shear at the junction. 

Mr. ETCHELLS : — So you consider the total reaction 
made up of two factors — shear and friction. 

Mr. RYYES :— Yes. 

Mr. ETCHELLS : — The proportions must be diffi- 
cult to fix. But I do not raise that question now, it is 
too complex ; but I might add one point, however, 
in which a question of practical engineering came 
in versus theory. Theory is perhaps as near as we 
can get to the truth, but theorists, as a rule, often 
take what they consider the chiefest factors. But the 
chiefest factors in their opinion are not necessarily 
the chiefest factors in fact. I heard of an American 
engineer who, prior to the San Francisco earthquake, 
had one of his assistants calculating the resistance of 
a dam in which the pressures and stresses were set out 
very nicely and prettily to the last decimal. The 
design was like this — 




TWENTY-FOURTH MEETING, March 14, 1912 169 

The chief engineer examined it and remarked : " Yes, 
that is a very nice design ; we will turn it this way 
up." Thus ! — 




The dam was built in that position and it with- 
stood the earthquake, which the theorist had not 
allowed for. 

Mr. MORGAN E. YE ATM AN, M.A., M.Am.Soc. 
C.E., M.C.I. : — I do not know that I have much to 
say, Mr. Chairman. I might say, with reference to 
the new Croton Dam and the question that Mr. Marsh 
raised, that I think Mr. Ryves is right, that the 
figures sometimes given for the height of the dam are 
misleading. I forget what the actual maximum figure 
is — something like 280 ft., but that is really from the 
bottom of some excavations in the foundation which 
were made to get down to sound rock, and there is 
no section of the dam of the proper outline of 280 ft. 
high : 280 ft., I think, is the height from the top of 
the dam to the bottom of the lowest point of the 
foundation, but these foundations are irregular holes 
dug over a base of a very wide extent in order to 
get down to sound rock. The facts are perfectly 
irrefutable that that is the greatest height of the dam. 
but there is no vertical section of the full width of 
base corresponding to this height. 

I did not quite understand the lay out of all these 
parallel sections in Fig. 1 or how their thickness is 
regulated. The width of each section on the face of 
the dam naturally increases down towards the bottom, 
as the pressure increases ; but when you run down 
along the lines drawn there from the face down to 
the bottom, does each section remain of the same 
width, or does it gradually thicken out down to the 
bottom ? 



i/o THE CONCRETE INSTITUTE 

Mr. RYYES : — It increases to the middle, and after 
the middle it remains stationary. 

Mr. YE ATM AX : — From the highest point of the 
section it seems to me to be drawn as of the same 
width all the way down. But take the middle of the 
face ; it widens from the water -face down, does it 
not ? 

Mr. RYYES :— Yes. 

Mr. S. BYLAXDER, M.C.I. :— I did not intend to 
speak, only one point that very often is forgotten 
in considering the right theory to apply in connection 
with a dam is this, that many assume a dam to stand 
on rock which is not elastic and which will not give 
under pressure to any considerable extent. It is, of 
course, not the case. The rock will give or change 
its thickness in a similar way as a structure subjected 
to stress will. It can, as the previous speaker has 
mentioned, be demonstrated very nicely and very 
simply by making a section of a dam in jelly and 
subjecting one side to pressure. Then it can easily 
be seen how the jelly is deformed and shows the in- 
tensity of the pressure. Suppose yoa take a section 
and draw a horizontal and vertical line, thus producing 
squares, then producing a pressure on one side of 
the dam, the squares would be deformed, and the more 
they are deformed the greater the pressure. There 
must be a difference in pressure at different layers, I 
should say. 

MONS. MAURICE BEHAR, M.C.I. :— The only 
thing I can say with regard to the statement of Mr. 
Ryves, that reinforced concrete is not suitable for high 
dams, is that I do not see any reason for not using 
reinforced concrete, i think high dams in reinforced 
concrete can be executed, and as far as the cost is con- 
cerned they would be very much cheaper. This is 
especially true when we consider the large quantity 
of materials required for masonry or earth dams. 

Another reason in favour of reinforced concrete 
concerns the question of excavations. By the distance 
between two buttresses the excavations would be 
reduced considerably in high dams. 

I cannot now give correct data concerning this 
matter, but it seems to me that reinforced concrete 



TWENTY-FOURTH MEETING, March 14, 1912 171 

could be adopted, in certain cases, for the purpose of 
high dams. 

Personally, I have read of works of that kind in 
masonry. There is one, for instance, called " Barrage 
de Furens," near St. Etienne, in France, built by 
Mr. Hirsch, Professor at the Ponts et Chaussees School,, 
in which the masonry works partly in tension. 

The figures of this barrage are not exactly in my 
mind, but I think the base is 7 metres or cS metres 
for a height of 50 metres or 60 metres of water. The 
dam is more than thirty-five years old. 

In reinforced concrete the thickness of walls would 
be reduced considerably, compared to the above, except 
the buttresses, which would remain very wide ; bat 
the total amount of materials in the work would be 
reduced considerably, compared to those in masonry 
or earth. 

Mr. A. ALBAN H. SCOTT, M.S.A., M.C.I.:— 
Simply as an innocent architect, ignorant of these 
great engineering works, perhaps I might intrude on 
the discussion and ask whether on all these interesting 
questions some lessons have not been learned from 
what I may call the rather considerable number of 
failures which have happened in dams. There is one, 
I think comparatively recent, in America, a fair-sized 
dam, which is a very bad failure, and surely from that 
some of these questions which have been argued this 
evening can more or less be determined from practical 
experience rather than upon theory. 

There is just one other question on Figure 10. It 
seems to be rather curious, that arrangement. It 
appears that there are no means taken for preventing 
the water from getting underneath the upstream side 
of the dam, and if that is so does not that have any 
weakening effect or any effect on the stress taken 
up by the dam, by giving practically a free passage 
or water to probably two -thirds the width of the base, 
and with that water there, does not that reduce all 
questions of relying upon friction ? 

With regard to reinforced concrete dams, the author 
simply makes the statement that they cannot be done 
to a great height. He does not give the reasons, and 
I think with Mons. Behar there cannot be any reason, 
if you can build in other forms of concrete to any 
height, why you cannot build in reinforced concrete. 



ij2 THE CONCRETE INSTITUTE 

In a place like India the question of variations of 
temperature and the consequent contraction and expan- 
sion of the dam might entirely throw out all one's 
calculations for portions of it. But that, after all, is 
perhaps only a question of the thickness of the pro- 
tection to the steel used for the reinforcement. But 
from an engineering calculating point of view I do 
not see why there should be any difficulty. 

I am sorry to intrude on this discussion, Mr. Chair- 
man. I am not competent in any way to talk about 
dams, but these few points were of special interest to me. 

MR. W. PERKINS. M.C.I., District Surveyor for 
Holborn : — The author has stated that he thinks it is 
impossible to construct a dam in that form with rein- 
forced concrete, and other speakers have dealt with 
that point. May I ask if it would be possible to 
construct a dam of that section in a compound way 
by using masonry for one portion of it, the buttresses, 
and by using reinforced concrete as a slab, instead of 
the arches ? 

Mr. R. DUDLEY, Assoc. M. Inst. C.E. :— There is 
one question, sir, I should very much like the author to 
give us some information about, because his paper is 
so extremely interesting, especially to me as an Indian 
engineer. He has spoken of the question of treating 
the substratum on which the dam rests, and he has 
treated it as if it was known before he designed the 
dam — as if the substratum was exactly known. In a 
dam that I was connected with in South Wales we 
made some beautiful calculations, but when we came 
to excavate the rocjc we struck an old coal level, and 
on another dam that I know of a vein of sand going 
down about 50 ft. in one place was met, so that 
any calculations you make based on the assumption that 
you are going to meet rock and strata, which you 
may set out as you have shown in Fig. 10, may require 
much modification when the exact nature of the ground 
is known and non -bonding is difficult. 

I have no printed paper by me, and I am rather at a 
loss in quoting. I think Mr. Ryves was going to treat 
the middle -third in one way and the upstream third in 
another, and the downstream third in another, tension 
and bonding, and not bonding. 



TWENTY-FOURTH MEETING, March 14, 1912 173 

Mr. RYVES : — Gradually increasing bonding from 
the front to the back. 

Mr. DUDLEY : — Well, if you strike a vein of sand, 
you have to go down with your concrete or your 
puddled trench. It would be very interesting if the 
author would kindly explain how his design would 
be modified to meet such a state of things. 

Mr. ETCHELLS :— A reinforced slab across the 
coal-hole would fill the bill, I think. (Laughter.) 

THE CHAIRMAN (Mr. E. P. WELLS) :— In look- 
ing at the various designs, and especially the author's 
thrust buttress dam, I do not see why reinforced con- 
crete should not answer with the heights that he has 
given, and also show a very considerable saving in 
cost. The suggestion that I should like to make is 
this : that for a height of 100 ft. up, instead of his 
thrust buttresses being at centres of 60 ft., he should 
place them at 30-ft. centres so that the arches on 
the face, to resist the maximum water pressure, would 
be 30-ft. span, as against 60 ft., and so only 
have a quarter of the horizontal thrust. It then 
becomes a question as to whether the extra amount 
of material that you will have to put into your but- 
tresses would cost more than the extra material put 
into your arch for a 60-ft. span as against a 30-ft. 
span. 

One practical suggestion I should like to make 
is that if the author constructs a dam of that size, 
instead of having a perfectly plain surface on the face, 
that it should all be in a series of steps of about 18 in. 
The reason that I suggest this is, that in erecting 
you can carry the whole of your scaffolding along 
with perfectly level bottoms, and it can be lifted up 
from the bottom to the top, and the same scaffolding 
used throughout the entire length ; whereas if you 
have a plain surface that anything can slide upon, it 
becomes a most difficult matter for construction, and 
very much more costly. That is one of the points 
which struck me, and which I think would make a 
great difference in reducing the cost, and it would not 
be more difficult to make the joints tight than it 
would by having the joints at right angles to the face. 

With regard to the question of reinforced concrete 



174 THE CONCRETE INSTITUTE 

I do not see any reason why it should not be done in 
that material. In fact, the stresses that the author 
shows on the stonework did not amount to more than, 
I think, 12 tons or 14 tons a foot on the base. 

Mr. RYYES : — Ten tons a foot on the base. 

THE CHAIRMAN (Mr. E. P. Wells ):— Well, it 
is a very, very poor plain concrete that will not resist 
the 10 tons a foot, and I think even the Eondon 
County Council permit 12, so that if you use rein- 
forced concrete the cost could very considerably be 
reduced. In fact, I think that if the author were to 
go into the matter carefully, even with the increased 
cost of cement in India, he would find the 1 laximum 
total weight that he would have in his foundations, if 
in reinforced concrete work, would possibly not exceed 
5 tons to 6 tons per square foot, especially when you 
can take into account that if he places his buttresses 
at centres of about 60 ft., and inverts the arches in 
between the same, he has got an enormous area over 
which to distribute his load. There is one question 
raised also about excavation. If it is a question of 
cost, of going down to obtain a very hard bottom, then 
it means a very considerable saving. 

After these few remarks I now propose a most 
hearty vote of thanks to the author for the paper which 
he has read, and I will now call upon him to reply to 
the various speakers. (Applause. ) 

Mr. RYYES : — The various points that have been 
put forward show that the paper has dropped on 
matters that are of interest. I think I might say first 
of all, in reply to the remarks of several gentlemen, 
that I have not made calculations to show that a rein- 
forced concrete dam up to 180 ft. high, on the 
principle of my thrust buttress dam, could or could 
not be built. I said that reinforced concrete could 
not be used economically for very large dams, and 
I have no doubt whatever that there is a limit in height 
under ordinary circumstances beyond which the rein- 
forced concrete dam becomes too expensive, simply 
because the materials are too expensive. Portland 
cement is an expensive material, and the very poor 
stuff that would stand 1 o tons per square foot may 
be very cheap stuff. 



TWENTY-FOURTH MEETING, March 14, 1912 175 

Under different circumstances, of course, it is pos- 
sible that a reinforced concrete dam could be built to 
a great height, and such a case as that of the Furens 
dam, which is 183 ft. in height and is built to a 
radius of only 823 ft., and is in a narrow gorge, points 
that way. A dam of that sort might very well be 
built of reinforced concrete, but my paper was really 
confined to the consideration of the case of a dam 
across a wide valley. When you want an enormous 
quantity of materials, you must spread out your loads 
upon a large base ; and you do not want to concentrate 
your loads. If you have a material which will carry 
easily 20 tons to the square foot, and by means of that 
material you transmit loads down to the ground and 
ti en have to spread it all out again to bring it down 
to a few tons per square foot, that is an expensive 
process. It can very readily be done for security and 
with safety in calculation, but it is an expensive 
process. 

It seems to me that the thrust buttress type of 
dam hits the happy mean in collecting the water loads 
and concentrating them only to a small extent, so that 
it only has to spread them out again to a small extent 
when it reaches the rock, or not, perhaps, spread them 
out at all. 

I will now take the questions as they came in order. 
Mr. Marsh asked whether the buttress of the parallel 
slice dam is intended to be built with vertical sides, 
so that the arches are all the same span the whole 
way up — the arches or spans, whatever they might 
be. That is so. The point in connection with that 
type is that you avoid going away from the ordinary 
theory altogether. If the theory will hold in the 
case of a buttress with the sides exposed — vertical 
sides— you do not want to tempt Providence any further 
by battering the sides or by altering the shape in any 
way ; you want to treat it as if it were a portion of 
an ordinary mass gravity dam. 

About the New Croton Dam, I think that the correct 
height is 238 ft. for anything like a considerable 
section, and, as another speaker said, if there is a 
greater depth it is only a hole filled up with masonry. 
As a matter of fact, all the base of the dam is nothing 
more than a hole filled up with masonry. They made 



176 THE CONCRETE INSTITUTE 

a big hole in the world, they filled it with concrete, 
and on the top of that they built a dam 150 ft. 
high. Then they said they had got a dam 238 ft. 
high. If you are to make a solid hole in the world 
at a greater depth than that, fill it in with concrete and 
build on that, it is not the same thing as a free dam 
in free air. There is all the difference between an 
aeroplane running on the ground and an aeroplane 
in free air. You cannot fall from the one and you 
can fall from the other. 

Such a dam may topple over at any plane in its free 
height ; it cannot topple over at its base, so that the 
question of security does not come in at all the same 
way. 

With regard to my own opinion about p sec 2 <p, I do 
not want to bear the burden of that opinion. It is 
everybody's business, and the mathematicians have 
developed the theory. If near a surface of masonry 
you have a vertical pressure, p, then at the surface of 
the masonry you have a pressure p sec 2 (/>. The 
vertical component of the pressure at the downstream 
face of the dam is probably much less than p — that is, 
you do not adopt the straight line of distribution, 
the sloping straight -line curve of pressures on the 
base. If that straight -line curve is correct there is 
tension under the dam. Then as to the reinforced 
concrete, I have a note here that the small reinforced 
concrete dams that have been built are not thrust 
buttress dams, because they are calculated as gravity 
dams. I think you will find, those who are interested 
in the matter, after going into it, that no dam has been 
designed as a thrust buttress dam. Several dams in 
America have been designed with some reliance being 
placed upon the fact that a part of the water load was 
transmitted to the rock directly, but those dams are 
designed as gravity dams on the toppling-over theory. 
Portions of them are not so placed that they transmit 
water thrust directly to the bottom. You will find, 
even in the small dams, that those small dams do 
not quite act as thrust dams. They transmit the lower 
part of the water load to the rock, but not the upper 
part of it. 

Another of Mr. Marsh's points was with regard to 
Fig. 11. That drain through the dam is a sluice. 



TWENTY-FOURTH MEETING, March 14, 1912 177 

In damming rivers you often have to provide a sluice 
through the dam, so if you let the water from the 
lower portion of the face reach that point, the only 
head of water against the lower part of the face is 
due to the head up to the level of the sluice. I am 
not supposing that you cut the drain through there 
solely for the purpose of draining it. If I did, I 
should put it well below the surface of the ground, 
perhaps 20 ft. or so ; - but having, as in many cases one 
has, a sluice in order to keep down the silt, that sluice 
is a very convenient way of connecting up to the lower 
part of the face. 

With regard to Mr. Marsh's other point, about 
keeping the " plums " apart, I certainly did contem- 
plate keeping them quite a foot apart. 

There are some points raised by Mr. Andrews that 
I will not go into now. I also had the advantage of 
having sat at the feet of Professor Karl Pearson, and 
if I had not I do not know that I should have read 
this paper. I could show Mr. Andrews, perhaps, some 
papers which he might look at in connection with the 
matter, but I could not go into the theory now, as 
suggested ; I could not go into it very well in connec- 
tion with this paper, which is a practical paper 
entirely ; I am taking certain things for granted. 
If there is any advantage in going thoroughly into 
the matter in any other way, I am very ready to do 
it ; I have got any amount of material. 

But I would like to say that I worked out the ques- 
tion whether there is tension in the under side of the 
dam or not, and I went on modifying the straight -line 
distribution of pressure until I found there was no 
tension ; but adopting the straight -line theory of dis- 
tribution of pressures under the dam, I found that 
there is tension. Instead of working in horizontal 
layers, the usual way in which you work out the 
stresses in a mass dam by dividing it into imaginary 
horizontal layers, I divided it into imaginary vertical 
layers, and I found that I definitely got strong tension ; 
I then modified my curve of pressures until I got 
no tension, and I said, " Let us assume, believe, or 
hope that is the true curve of pressures." 

All the engineers who study the subject evidently 
believe that the maximum of the curve of pressures 



178 THE CONCRETE INSTITUTE 

is a little before you get to the toe and not quite at 
the toe. That is shown in the article I have referred 
to in The Engineer. 

Then as regards the bonding into the rock on the 
upstream side, I do not believe in making a trench 
at the upstream toe at all, because I think that causes 
tension. I worked out a number of mathematical 
examples in the same way, using imaginary vertical 
strips, and assuming the dam was fixed at the upstream 
toe and afterwards assuming it was fixed in the upper 
half, middle half, and towards the downstream end. 
If you work it out graphically you get, in the first 
two cases, very severe tension in the under side of the 
dam, and, when you come to think of it, it is only 
natural. I made extreme estimates for the sake of 
getting definite results, but those extreme estimates 
in an exaggerated form brought out what are actual 
facts in actual practice. 

As to Mr. Etchells's point about the verification of 
formulas, I propose to make a summary of some kind, 
or at any rate to go into the materials I have got, and 
if anything can be usefully put forward in a simple 
form I am very ready to do it. Alluding to Figs. 
9 and 7, I think some explanation was asked, of how 
I got this p sec 2 <p, and I think I will put that in 
the same boat as the other points to be gone into, if 
I can put them in a convenient form for ready 
reference. 

As to shear, whether this is shear or whether it is 
friction under the dam, I want only friction at the 
upstream end because I want the dam to move rather 
than the rock. I think trenching tends to split 
the rock at the upstream toe, and I want to develop 
compression as far as possible. The resistance should 
be as far as possible in the form of shear towards 
the downstream toe. That is based upon those cal- 
culations that I made in which I found tension under 
various circumstances, but not if you fixed the down- 
stream end. I have got one or two diagrams showing 
the sun and the different Signs of the Zodiac which I 
will show to Mr. Etchells. Perhaps he would like 
to suggest their being put among the further notes. 

Mr. ETCHELLS :— I do. 



TWENTY-FOURTH MEETING, March 14, 1912 179 

Mr. RYVES : — Then in reply to the point raised 
by Mr. Yeatman as to the New Croton dam, that has 
already been dealt with. 

Then as to the thickness of the slabs in the buttress 
in the thrust buttress dam, Fig. 1, the water load 
comes upon the slabs at their ends, and as the slabs 
go down underneath the masonry, which is above them, 
I go on counting in the component at 45 due to the 
weight of the masonry above them. So, until you get 
to the middle line under the apex, the buttresses go 
on increasing in width ; then, as the load does not 
increase after that, the width does not alter. The 
buttresses being parallel to the other face, the load 
does not increase, so the buttress keeps the same width. 
It widens out to the middle line and then keeps that 
width the rest of the way. The weight of the masonry 
is fully taken into account. And to meet another 
point I have not taken the vertical component as a 
matter of any importance, because the bottom of the 
dam is supposed to be a zig-zag at 45 , so the pressure 
would only be 45 one way or another ; you would 
not get any vertical component because you have no 
horizontal base. 

As for building high dams in reinforced concrete, 
as I say, I have not worked out examples, but my 
point is that those who think they can be built had 
better work out the examples. They are much more 
competent than I am to work out the cost of a very 
high dam in reinforced concrete, and I think it much 
better that they should do it and let me criticise them 
than that I should put forward a possibly weak and 
inefficient design and have that criticised. 

About lessons from failures ; I have studied the 
recent failures of dams in the United States, and I 
have not found any useful lessons in them at all 
except not to do it like that again. We should not 
have done it like that before. There are no 
failures in India, I think, of any big important works. 
They are, at any rate, very rare indeed, and we very 
seldom have failures in important works in England. 
The condition of affairs in America is different. 
Things have to be done comparatively in a hurry. I 
do not believe these failures teach you anything. I 
believe one could learn something from a recent 



180 THE CONCRETE INSTITUTE 

failure of a Spanish dam, but I have not got any 
particulars of that. 

As to what I should do if I came upon a deep 
crevice in the rock in order to fulfil the conditions of 
Fig. 10, I would till up the crevice with masonry and 
reduce the surface as far as possible to a surface 
similar to the rock. But if it was near the downstream 
toe I would bury it right into the dam. If near the 
upstream toe I would fill it up to the level of the 
rock as far as possible, but, of course, with a very 
irregular bottom you cannot evolve any theoretical 
ideas as to how you are to make your foundations in 
that case. You take advantage of every surface which 
is more or less at right angles to your thrust, and use 
that. 

As to the Chairman's point about the buttresses 
being close together, the buttress at the base is 38 ft. 
wide in the front, and that means that the span of 
the arches is small. If you look at Fig. 1 you will 
see that the thickness of the arch ring does not increase 
from the top to the bottom in proportion to the head 
of water above it. That is because the span is getting 
less and less. I do not think there are any other points 
that I can usefully go into now, and it is getting rather 
late. 

The meeting then terminated. 

[It is hoped to include some further notes on the 
subject by Mr. Ryves in the next issue of the 
Transactions. 



TWENTY -FIFTH ORDINARY GENERAL 
MEETING 

Thursday, April i i, 191 2 

THE TWENTY -FIFTH ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296, Vauxhall 
Bridge Road, London, S.W., on Thursday, April 11, 
191 2, at 8 p.m., 

Sir HENRY TANNER, C.B., I.S.O., F.R.I.B.A., 
F.S.I., etc. (President) in the Chair. 

The following were elected members of the 
Institute : — 

Mr. Hugh Cecil Forder, Westminster. 

Mr. Philip Leonard Francis, Westminster. 

Mr. Hubert Haughton, Westminster. 

Mr. Charles Benjamin Ife, Westminster. 

Mr. Richard Goulburn Lovell, A.R.I.B.A., 
M.S.A., Eastbourne. 

Mr. Thomas de Courcy Meade, M.Inst.C.E., 
F.S.I., etc., City Engineer, Manchester. 

Mr. Edward Meredith, Stud.A.R.I.B.A., Llan- 
drindod Wells. 

Mr. Joseph Edward Mundell, A.R.I.B.A., 
F.S.I., M.R.San. I., London. 

Mr. Antonio von Osenbruggen, Westminster. 

Mr. Albert Ovenden Pitt, Westminster. 

Mr. FRANK RADCLIFFE, Little Royd, Huddersfield. 

Mr. Walter Cawthorne Thorneley, West- 
minster. 

Mr. Bertie Carloss Wheatcroft, Westminster. 

THE SECRETARY (Mr. H. Kempton Dyson) 
announced that the following had been admitted as 
Students of the Institute : — 

Mr. Edgar Albert Burke, 

Mr. Noel Edward Creasy, 

Mr. Joseph Harold Doswell, 

Mr. Victor Haiden Knight, 

Mr. Perciyal St. John Parkinson, 

Mr. Cecil Jacob Pell, 



i82 THE CONCRETE INSTITUTE 

Mr. .Mark Pitter, 

Mr. Reuben Stubbs, and 

Mr. Thomas S. Vandy, all of Westminster. 

Mr. G. C. WORKMAN then read Mr. MAURICE 
BEHAR'S paper entitled, " The True Bending 
Moments of Beams with Various Degrees of Fixity," 
as follows : — 

THE TRUE BENDING MOMENTS OF BEAMS 
WITH VARIOUS DEGREES OF FIXITY. 

By MAURICE BEHAR, Civil Engineer (Ecole des Ponts et Chausscesi. 

Although most of the countries in Europe have official 
regulations for reinforced concrete works, there is no regula- 
tion of this kind in Great Britain yet, and architects and 
engineers have so far been governed by the First and Second 
Reports of the Royal Institute of British Architects' Joint 
Committee, or by the usual practice of the various firms of 
specialist designers. 

I understand, however, that Official Regulations are now 
proposed, and that these will shortly be adopted for rein- 
forced concrete works, not only within the radius of the 
County of London, but for all such works as come within the 
scope of Local Government officials, and I fear that if certain 
principles and formulas are introduced into these Regulations, 
concerning which there has recently been a certain amount 
of controversy, the progress of reinforced concrete may be 
severely hindered. 

The object of this paper is to discuss each of the prin- 
ciples and formulae which I have mentioned above, and also 
to show, by means of examples, the excessive increase in the 
weight of the steel bars in beams and posts in reinforced 
concrete, due to the application of these methods. 

I shall first consider the case of beams. Until now almost 
all the engineers specialising in reinforced concrete calculate 
these elements by applying the usual laws of mechanics, or, 
in other words, the laws governing the strength of materials. 
Nevertheless, for the main beams and secondary beams fixed 
at their extremities to other members in reinforced concrete, 
such as walls, posts, or other beams, the specialist engineers 
usually admit that a certain amount of fixity takes place at 
these points of junction, and concerning this it is usual to 
make certain assumptions. 

Some engineers consider that the fixation is partial on the 

support, and has for its value . In this case they ealcu- 

-4 



TWENTY-FIFTH MEETING, April ii, 1912 183 

late their moment at the middle of the beam, sufficiently 

WL 

strong to resist a bending moment of , which is the 

corresponding moment to the one stated above. 

Other engineers, and we think they are in the majority, 

WL 

consider that the bending moment should be in the 

* 10 

middle of the beam, and in this case they provide at the 

points of support a section of steel capable of resisting a 

, WL 
corresponding moment of 

Again, other specialists consider that reinforced concrete 
beams extending over several spans must be considered as 
continuous, and they apply to the calculation of these beams 
the usual rules governing continuity. 

In addition to the three above-mentioned methods of 
calculating a beam in reinforced concrete fixed upon its two 
points of support, it is now my intention to consider the 
method which has been put forward for official sanction, and 
which would have the effect of stipulating a bending 

WL WL 

moment of in the middle of the beam and — at the 

12 12 

points of support. 

Of these four methods of calculation, let us consider the 
question of which one produces the maximum of safety in 
the construction. 

1. Let us assume that the bending moment in the middle is 

, and that the corresponding moment at the points of 

support is — . It may happen that on account of the con- 
tinuity of two consecutive beams and the distribution of the 
loads on the spans, that the moment at the point of support 
becomes greater than the one provided for. In this case 
fissures will occur at this point. 

Let us now assume by exaggeration that these fissures 
render the points of support absolutely free. The middle of 

WL 
the beam will then support a bending moment equal to -g-, 

but as the beam has been calculated for a bending moment 
in the middle of — — , the factor of safety will become 



1 X — = 2 - 666 instead of 4. 
^ 12 



184 THE COXCRETE IXSTITUTE 

The beam will not collapse on this account, inasmuch as the 
concrete in the lower part of the beam situated underneath 
the neutral axis is working in extension, which has not been 
taken into account in the calculations. 

2. Let us now assume that the bending moment in the 

middle is and the corresponding moment at the sup- 
ports is equal to . The method of reasoning is the same 

as for the above, except that in the case of the transforma- 
tion of the point of support into a free support the factor of 
safety becomes 

4 X — = X2 instead of 4. 
-t IO J T 

3. Let us now consider the continuous beams. In this 
case the moments at the supports are generally greater than 
WL 

12 

Concerning the moments in the middle of the spans, they 

will often be much less than - — . We must remember, 

12 

however, that although in structural steelwork it is possible 
to obtain perfect continuity between two consecutive spans, 
it is not so with reinforced concrete, where the continuity 
depends upon the adherence of the concrete to the bars pro- 
vided in the upper portion of the beam at the points of 
support. 

I am of opinion that the method of constructing consecu- 
tive beams in reinforced concrete does not ensure such 
perfect continuity as that which may be obtained in con- 
secutive metallic girders. If owing to this lack of solidarity 
between two consecutive spans, or if owing to bad construc- 
tion the point of support should give way and become 
transformed into a free support, then the middle of the 
beam, which may in certain cases have been calculated with 

a moment less than , will have a factor of safetv less than 

12 

2 - 66, and in certain cases even less than 2. It is obvious 

that the construction in this case becomes endangered, and 

the danger is all the greater because if one of the beams 

gives way the others will give way in turn, on account of 

the fact that the continuity upon which we relied will have 

disappeared owing to the failure of the first element. 



TWENTY-FIFTH MEETING, April ii, 1912 185 

It is for this reason that in steel construction, when there 
are several continuous spans, it is usual to divide these into 
a series of portions of three or four consecutive continuous 
spans, each portion being separated by free supports. 

4. If we consider in the middle and at the points 

T 12 12 * 

of support, this case certainly has the effect of producing a 
greater safety than those above mentioned. In the middle 
there is the same drawback as in the first case, but not 
the one clue to continuity. At the supports, however, this, 
case is weaker than the case of continuity, although it has 
very nearly the same value. On the other hand, the latter- 
method obliges the engineer to provide, as in the case of 
continuity, in the bottom compressed portion of the beam, 
and at the points of support, a considerable section of steel, 
and this section will be all the greater at these two points, 
on account of the fact that, if this principle is admitted in the 
Official Regulations, the section of steel required will have to 
be calculated by applying a stress in the steel equal to fifteen 
times the stress of the concrete, taken at the axis of the rein- 
forcement employed. 

Now, as a matter of fact, a large number of examples of 
principal beams and secondary beams which I have calculated 

with at the supports, have proved to me that the 

working stress of the steel in compression is always below 
8,000 lbs. per sq. in., and that in secondary beams this 
stress rarely attains 6,000 lbs. per sq. in. The result is 
that one is often obliged to provide such a considerable 
number of steel bars, that it is materially impossible to place 
them in the small compressed area of the concrete, in the 
bottom of the beam. 

A close examination of the four methods of calculation 
mentioned above has led me to conclude that as far as 

stability is concerned, the moment of — — in the middle 

WL WL 

and at the supports gives a greater security. - — or - ^ q - 

. WL 
at the supports and their corresponding values of — or 

^ in the middle would never actually cause the collapse 
10 . 

of a beam. The most that could happen in such a case 
would be, that the floor slab over the beams would show 
fissures, whereas, if we consider the case of continuity, we 



1 86 THE CONCRETE INSTITUTE 

find that this may prove dangerous if the workmanship is 
bad or the materials unsuitable. 

From an economical point of view, the semi-fixation with 

r WL , , WL 

moments of at the support and — — at the middle, 

requires about the same amount of steel as the partial 

fixation with moments of - at the supports and at 

40 ri 10 

the middle. 

WL , , WL . , 
Concerning at the supports and 111 the middle, 

when it is possible to actually construct the beam by accom- 
modating" the amount of steel required, I have found that 
these values bring about an increase 40 to 50 per cent, 
greater than required in the cases of semi or partial fixation 
mentioned above, and that in certain cases the excess of 
steel may be as much as 100 per cent. 

Concerning the case of continuity, if we are obliged to 
provide in the lower portion of the beams the necessary 
section of steel to take up the compression at the points of 
support, and if we put aside the method which consists of 
reinforcing this portion by means of spirals, the weight of the 

WL 
bars would be less than that clue to at the supports and 

in the middle, but the weight of steel would be superior to 
that produced by the formula of semi or partial fixation. 

I understand that for various reasons the method of re- 
inforcing the concrete in the beams by means of spirals 
would not be considered or authorised in the new Regula- 
tions, and it is doubtful whether this particular method could 
meet the difficulty in an economical manner. If, however, 
the new Regulations were to allow the use of spirals, to 
increase the compression of beams, and if it was found that 
this was the only possible way of solving the difficulty of the 
compression, then it is obvious that the Regulations would 
have the effect of favouring, to the exclusion of all others, 
one particular method only for which a patent has been 
obtained, thereby creating a monopoly. 

It is therefore absolutely necessary that the proposed 
Official Regulations should not have the effect of obliging 
engineers to calculate beams fixed at both extremities 

with a bending moment of at the supports and 

WL 

— — at the middle, and I sincerely trust that the authorities, 



TWENTY-FIFTH MEETING, April ii, 1912 187 

who are at present drafting out new Regulations, will simply 
stipulate the application of the usual laws of mechanics for 
the determination of the dimensions of beams in reinforced 
concrete ; and also hope that the case of semi-rixed beams, 
which is in no ways empirical, and which is absolutely in 
conformity with the laws of mechanics, shall be considered 
and shall find its proper place in the new Rules. 

Compression in the Upper Portion of the Beams and 
in the Middle of the Span. 

I understand that it is intended to introduce in the new 
Rules a clause stipulating that the width b of the slab working 
in compression together with the beam shall be equal to the 
smallest of the following values : — 

(a) To one-third of the effective span of the beam. 
(6) Or three-quarters of the distance centre to centre 
between beams. 

(c) Or six times the thickness of the beam. 

(d) Or fifteen times the thickness of the slab. 

I have found that the cases c or d are those which will be 
usually applied, especially for principal beams. It is obvious 
that owing to this the compression will almost in every case 
be insufficient at the centre of these beams. As, on the other 
hand, the upper bars are usually placed 2 in. from the upper 
surface of the beam, the working stress of the steel will 
rarely reach 8,000 lbs. per sq. in. We shall therefore 
be obliged to provide a relatively considerable section of 
steel in the top portion of the beam, and in certain cases 
this section might even exceed the section of the steel in 
tension, unless the Rules authorise engineers to consider the 
beam in the middle as being practically a steel girder, and in 
this case the sections at the top and at the bottom would be 
equal ; but of course the compression of the concrete would 
have to be neglected. 

Now, if we examine a reinforced concrete construction 
composed of slabs, secondary beams and principal beams (for 
instance, floors or retaining walls), the construction presents 
an absolutelv monolithic and rigid table, and as the com- 
ponent members are working together, I would suggest that 
111 reality it would be possible to assume that the entire 
distance between centre to centre of the secondary beams or 
main beams is working in compression. In other words, that 
the entire area of the slab could be taken for the resistance in 
compression of the beams. 

The only objection to this method of procedure is that to 



188 THE COXCRETE INSTITUTE 

the compression of the slab itself considered separately we 
must add the compression produced by the secondary beams ; 
that is, if we only consider a slab and secondary beam. 

If we consider the principal beams we find that to the com- 
pression produced by the latter we must add the compression 
due to the secondary beam. It is possible that the resultant 
of these two forces may produce a compressive stress 
superior to 600 lbs. per sq. in. especially in the case 
where the compression of the slab is working with the 
secondary beam, inasmuch as the slab itself is usually calcu- 
lated for a stress of 600 lbs. at the extreme compressed fibre. 
but when the slab is working with the principal beam it is 
only influenced by the compression of the secondary beam, 
and as in reality the entire table or slab is working in the 
direction of the secondary beams as well as in the direction of 
the principal beams, the result is that the rates of compression 
at the extreme compressed fibre are comparatively low, and 
the resultant rarely attains 600 lbs. per sq. in., except in 
the case where the sectional area of the concrete being 
insufficient, the designer has been obliged to introduce a 
certain section of steel in compression. 

It follows from the above method of reasoning that it 
would be possible to retain the clauses a, b, and d for the 
secondary beams, but that it would be advisable to suppress 
the clause c, which I consider is unnecessary as applied to 
secondary beams, and I am of opinion that clauses a and b 
only should remain for the principal beams. 

It is perhaps for the reason mentioned above that the 
French Regulations for reinforced concrete stipulate that 
three-quarters only of the slab application must be taken for 
the compressive resistance of secondary beams, or one-third 
of the span of the beam, whichever is the smallest ; but it is 
to be noticed that these Rules have not prescribed anything 
concerning the principal beams, so that in France engineers 
are free to take the entire width of the slab for the com- 
pressive resistance of the principal beams. 

I wish to make it clear that I do not actually advise that 
this should be done, but that clauses a and b should subsist 
for the calculation of the compressive resistance of principal 
beams. 

Reinforced Concrete Lintels or Beams without Slabs. 

I am under the impression that the proposed Regulations 
have not put forward any rules to deal with this case. If, 
therefore, we apply to these beams the formulae applicable to 



TWEXTY-FIFTH MEETING, April ii, 1912 189 

rectangular beams, we would have to take for the stress of 
the steel in compression fifteen times the value of the stress 
of the concrete at the centre of gravity of the section of the 
compressed bars, namely, about 8,000 lbs. per sq. in. 
A reinforced concrete lintel will therefore have a weight of 
steel often superior to that of a steel girder or joist, and on 
this account there would be no advantage in future in 
adopting reinforced concrete for this kind of work. 

I think it advisable to draw your attention to this matter, 
which is of great importance, and I trust that the authorities 
will see their way to investigate this particular case, and to 
either authorise engineers to design these lintels or rectan- 
gular beams without slabs as steel beams, namely, to allow 
the section of the steel to be calculated at the same rate in 
tension and compression, the compressive resistance of the 
concrete being neglected. 

Posts or Pillars in Reinforced Concrete. 

Concerning the calculations of posts or pillars, I take it that 
the formula which is intended to be adopted will be — 

P = c(A + (;// - 1) A.), 

in which c represents the working stress of the concrete in 
direct compression, A the effective area of the pillar — that is 
to say, the section of the pillar after deducting the area of 
concrete situated between the external faces of the pillar and 
the vertical bars, A : . being the section of the vertical bars and 
;;; equal to 15. 

Although this formula may be applied to the case in which 
the transverse reinforcement is taken into account, and where 
the diameter of the transverse reinforcement and the spacing 
of same per foot run would lead us to take for c much higher 
values than 600 lbs. per sq. in., I fail to see why this 
formula should be applied to ordinary pillars, seeing that for 
purely constructional reasons only transverse reinforcement 
has been introduced for the binding together of the principal 
bars during the concreting operation, and in this case it 
would appear to me that the total section of the concrete 
should be taken into account, which has been, and is, the 
usual practice of most of the experienced designers in 
reinforced concrete. 

If an additional stipulation is considered necessary for 
further safety, I would suggest that this should take the form 
of reducing the rate of 600 lbs. per sq. in. of the concrete in 
compression, in conformity with Rankine's formula. 



190 



THE CONCRETE INSTITUTE 



In order to clearly demonstrate the consequences of the 
application of some of the formulae and proposed Regulations 
above mentioned, I have studied a floor in reinforced con- 
crete resting upon beams and posts, also in the same 
material, and to this work I have applied strictly the con- 
ditions which would be enforced for the verification of such 
a scheme by the architect or engineer who would have to 
apply them. 



Fg J 




Fig. 1 shows a floor which is to carry a superload of 
1^ cwts. per sq. ft., the span centre to centre of the 
slab being 6-40 ft., the span of the secondary beams being 
15 ft., and that of the principal beams 32 ft. 



Slab. — Span 6-40 ft. ; thickness, 4 in. ; rendering, 1 in. 

168 lbs. 

63 „ 



Superload 
Dead load 



B, = Be 



Total per sq. ft 
231 x 6-4 



2^1 lbs. 



12 



= 788 ft. lbs. = 9456 in. lbs. 



TWENTY-FIFTH MEETING, April ii, 1912 191 

I have provided for the resistance to this bending moment, 
and for a width of slab of 1 ft. 0-22 sq. in. of steel in tension. 

Verification of the Slab. 

The position of the neutral axis is given by the equation : 



n = (Jni 2 r 2 + 2 mr — mr) d 

At 022 , 

111= k : )•=,-= = O'ooo 1 

3 bd 12 x 3 

// = ( J 225 x 00061 2 + 30 x 0.0061 — 15 x 00061)3 = 1 "0377" 

The lever arm of the bending couple is given by the 
formula — 

._,,-•" 3»_iSZ7 = 2 . 6545 » 

:> 3 

The tensile resistance moment is given by the formula — 

R, = tA,a = 17,000 x o'22 x 2'6545 = 9928 in. lbs. 

The compressive resistance moment is given by the 
formula — 

K, = - bna = 300 x 12 x 1*0377 x 2 '°545 = 99 x ^ in. lbs. 

The two moments of resistance R\ and R, being greater 
than the moment due to external forces, the slab is therefore 
under good conditions of stability. 

Secondary beam a. — Span, 15 ft. ; scantlings, 6 in. X 10 in. 
This beam supports, per foot run, a load equal to — ■ 

Slab and superload 6-4' x 231 = 1478 
Dead load = 63 

Total = 1541 lbs. 

B c = B, = I541 ^ I52 - 28,894 ft- lbs - = 346,728 in. lbs. 

I have provided to resist this moment — 

In the middle of the beam in tension ... 2-092 sq. in. 
At the points of support in tension ... 2^092 „ 

At the points of support in compression ... 7-42 „ 

N 



192 THE CONCRETE INSTITUTE 

I have not provided steel in compression at the upper 
portion of the beam in the middle, because the concrete of 
the slab is sufficient to absorb the effort of compression. 

i. Verification of the Resistance at the Middle of the Span. — 
The neutral axis being situated inside the slab, the position 
of the neutral axis is given by the formula — 

n = ( Jm 2 /- 2 + 2inr — mr)d 
in = 15 d = 10" 4- 4" — 2h" = ni". 

The width, of slab b working in compression at the same 
time as the beam is given by the smallest of the following 
quantities : — 

b — 075 x 6-4' x 12" = 57-6" 
6 . '-^^ = 60" 

b = 4" x 15 = 60" 

6 = 6x6" = 36". 

I have chosen 36". 

A, 2x92 

r = T-j = —7 = 0-0050^. 

b d 36 X II'S 3 3 

Substituting in the above equation we have — 



11 = ( J 22$ x 000505 2 + 30 x 0*00505 — is x 0-00505) ii*5 
n = 3-683". 

The lever arm of the bending couple is therefore — 

a = d - - = ii-s - =2— J = 10-273 • 
3 ^ 

The compressive resistance moment is equal to— 

R, = - bna = 300 x 36 x 3-683 X 10:273 = 408,623 in. lbs. 

The tensile resistance moment is equal to — 

R, = t\,a = 17,000 x 2092 x 10-273 = 365,349 in. lbs. 

The two moments of resistance being greater than the 
moment due to external forces at the middle of the span, the 
beam is therefore in «ood conditions of stabilitv. 



TWENTY-FIFTH MEETING, April ii, 1912 193 



2. Verification of the Resistance at the Point of Support. — The 
Second Report of the R.I.B.A. does not give any formulae for 
the determination of the position of the neutral axis in a 
reinforced concrete beam when, the compression of the 
concrete being insufficient, a certain section of steel is 
required in the compressed portion of the beam, and I 
understand that the proposed Official Regulations do not 
provide any formulae for this particular case. 

In order to verify the support, I have found it necessary to 
establish this formula by making use of the same theory by 
means of which the position of the neutral axis is established, 
when the compression of the slab is sufficient. 

3 



*r 



.* 



m 



-^ 



A- 



Let us assume that the moment of the extended section in 
relation to the neutral axis is equal to the moment of the 
compressed section also in relation to the neutral axis. We 
then have (Fig. 2) — 



mA t (d - n) = mk c {n - a) + b,u x 



or- 



b r n 2 + 2///(A c + A,) - 2m(A e a + A t d) 
hence we have — 



(I) H = 



i(A c + A t ) + s/m 2 {A c + A/) 2 + 2b r m(A c a + A^) 



If we neglect to take into account the small rectangle of 
the compressed concrete b r ti, we can find the position of the 
neutral axis by the following equation : — 

mA t (d — n) = mA c (n — a), 



i 9 4 THE CONCRETE INSTITUTE 

or — 

mA, + A,) = A«a + A..,/. 
A,o + A.i/ 



(2) // = 



A. + A, 



In a general sense, with the exception of beams of 
considerable span where the rectangle bn is comparatively 
important, the results given by the formulae (i) and (2) are 
almost identical. 

The formula (2) applied in the case which concerns us 
would give — 

742 x 2" 4- 2-OQ2 X 12" 

11 = — ; ~ = 4*20' 

7-42 + 2-092 ^ 

The formula (1) would have given // = 3-90". 

As the neutral axis comes within 4-20" of the soffit of the 
beam, it follows that the working stress of the compressed 
bars placed at 2' from this soffit, is- — 

15 x 300 = 4500 lbs. per sq. in. 

The lever arm of the bending couple at the point of 

support is — 

-T20 

a = 12" - ± — = ic-6o". 
3 

The compressive resistance moment will then be — 

R t . = 7*42 x 4500 x io - 6o = 353,934 in. lbs. 
The tensile resistance moment will then be — 

R, = 2-092 x 17,000 x io*6o = 376,978 in. lbs. 

These two moments being greater than the moment due to 
external forces, B, = 346,728 in. lbs., it will be seen that 
the beam is under good conditions of stabilitv. 

I would simply draw attention to the fact that by having 

\VL 
to apply at the supports we are led to provide in the 

compressed portion of the beam a section of steel equal to — 

2-092 J °"'" 
or, in other words, over three and a half times as much steel 



TWENTY-FIFTH MEETING, April ii, 1912 195 

at the lower portion of the point of support as the section 
which we have at the top. 

If we had taken into account the small rectangle of com- 
pressed concrete, this section of steel might have been 
slightly reduced, but as a matter of fact in the case of 
secondary beams it will be found that the section of steel 
required in the bottom portion of the beam at the point of 
support will always be at least equal to three times the 
section of the bars in tension. 

From a practical standpoint it appears to me difficult, if 
not impossible, to find a means of placing these bars in the 
section of concrete of which we would dispose, especially if 
certain restrictions have to be observed concerning the space 
to be left between the various bars. 

In the case which I have taken as an example the concrete 
has a section equal to — 

6x4^2 = 25-20 sq. in., 

and in this area we have to accommodate 7-42 sq. in. of 
steel. 

Assuming that we choose 5 bars if in. it is obvious that 
even these comparatively large bars will not be properly 
encased by concrete. 

Principal beam. — Span, 32 ft. Scantlings, 12 in. x 24 in. 

Loads per foot run : 

Slab, 15 ft. x 231 ft. = 3,465 

4x14x63 
Secondary beams — = no 

3 3- 

Dead weight = 300 



3,875 lbs. 
B,= B e =^ L -^ X32 2 = 330,667 ft. lbs. = 3,968,004 in. lbs. 

I have provided to resist this moment — 

In the middle of the beam in tension, 1005 sq. in. 
In the middle of the beam in compression, 974 sq. in. 
At the points of support in tension, 10-05 S( T m - 
At the points of support in compression, 22 sq. in. 



196 



THE CONCRETE INSTITUTE 



1. Verification of the Beam at the Middle of the Span : — 

Position of the Neutral Axis. — As we have steel in compres- 
sion, the formula — 

s, 2 + 2111 r 

"= / — ; \ 

2{s + inr) 

of the Second Report of the R.I.B.A. is not applicable. I 
shall therefore establish a formula which may be applied to 
this case, as I have already done for the support of the 
secondarv beam. 



/r 



.3 



6 



3j \ S <S 



s 



4c 



Let us assume that the neutral axis falls below the slab. 
The moments of the extended and compressed sections in 
relation to the neutral axis will give us the following 
formulas (Fig. 3.) : — 

///A. (J - //) = inA c (n - a) + bd s (11 — —J 

or else — 

// (bd s + niA c + in A,) — — - niA c a + niA.d 



hence — 



or 



in{A cU + A t d) + -^- 

II — ~— 

m (A c + A, + bds 
d = 24" + 4" - 2h" = 25-5" 
b - 075 x 15' x 12 = 135" 

b = 3--' X 12 = i2gM 
3 



or- 
or- 



TWEXTY-FIFTH MEETING, April ii, 1912 197 

b = 15 x 4" = 60 

6 = 6 x 12" = 72 

I have taken b - 60". 

60 x 4 2 
„ = 15 (974 x 2" + 10-05 x 25-5)+ — — = 8 . 6 „ 

15 (974 + IO '°5) + 00 x 4 
Arm of resistance moment :— ■ 
// 



a = d — 

3 3 



8-6 , „ 

- = 22'OX 



//& <■ 




—4 



Average compressive stress (Fig. 4): — 

d 4-63 
, _ 4 63 x c 
~ 8-63 
= 4-63 x 600 = 

8-63 d 

£ J 1 c; = 600 + 3'22 = 46llbs 



Compressive resistance moment : — 

R = a c -+-^(bd s +m.\) 

R = 22-63 x 461 (60 x 4 + 15 X 9-74) - 4,025,874 in. lbs. 



198 THE CONCRETE INSTITUTE 

Tensile resistance moment : 
R, = tAfO. = 17,000 x 1005 x 22-63 = 3.866,335 in. lbs. 

The moment of resistance to the compression is greater 
than the moment of the external forces 3,968,004 in. lbs. 

Concerning the moment of resistance to extension, this is 
less than 101,669 in. lbs., which is the moment due to external 
forces. This shows, therefore, that the steel in tension is 
slightly insufficient. We should therefore have to increase 
it by about — 

101,669 

— 7~— °* 2 8 sq. in . 

17,000x22-63 M 

2. Verification of the Beam at the Points of Support : — 

The position of the neutral axis is given, as in the case of 
the secondary beam, by the formula No. (2) — 

An + A J 

n = 



A t + A, ' 

= io - i6" 



22 x 2" + 10-05 x 26" 



22 + IO-O: 



If we apply formula No. (1), which is more accurate, we 
find :— 



_ - m(k c + A f ) N //» 2 (A C + A,) 2 + 2b r m( A t q + A t d) 
H ~ ~b7~ 



_ — r 5 x 3 2 °5 + J 22 S x 3 2 '°5 2 + 30 x 12 x (22 x 2 + 10-05 x 2 &) 



12 



n= - 48o75 + 583-30 =86 „ 

12 

The lever arm of the bending couple is therefore- 
a = d -— = 26" — — L - - 23-18 



The average compression of the concrete of the beam is 

= 300 lbs. per sq. in. Concerning the compression of 

the steel, if we admit that the centre of gravity of this 
section is at 2 in. of the soffit of the beam, which is a 



TWENTY-FIFTH MEETING, April ii, 1912. 199 

good average condition for the construction, we would 
have (Fig. 5) :— 

c_ = 8^46 
c' 6-40 

, 6-460 6-46 x 600 ,, 

c =" ^7T = w a = 4^9 lbs - 

^•46 840 ^- y 



/7<ST «5~ 



^-r 




The compressive resistance moment is — 

c 
R = (b,n X - + mk c c)a 

R = (12 x 8-46 x 300 + 15 X 22 x 459)23-18 = 4,2 17,044 in . lbs. 

This moment of resistance exceeds the moment due to 
external forces by — 

4,217,044 - -1,025,874 = 191,170 in. lbs., 

but, on the other hand, the section of the concrete in com- 
pression has been taken into account in the calculation 
of R c without deducting the 22 sq. in. occupied by the 
steel bars. 

We must therefore deduct from R t the following : — 

22 x 300 x 23-18 = 152,988 in. lbs. 

We see, therefore, that the 22 square inches of steel are 
absolutely required at each support of the beam in com- 
pression, and that this is due to the moment of -jj- 
at these points of support. As in the case of the secondary 



200 THE COX'CRETE INSTITUTE 

beam, I am of opinion that this section of steel is ex- 
cessive, and also that it is difficult to see how it is possible 
to properlv embed this section of steel bars, when the total 
sectional area of the compressed portion of the beam is — 

12 x 8 - 46 = 101 sq.in. 

I would also draw your attention to the fact that the above- 
mentioned results are all favourable to the engineer who has 
prepared the scheme, and might not strictly be in accordance 
with the requirements of a controller. As I have taken a = 2", 
whereas I ought to have taken this as equal at least to 4", on 
account of the considerable section of the steel, and with 
<7 = 4", it is obvious that we should obtain a section of steel in 
compression much greater than the one above mentioned. 

I would further draw your attention to the fact that in this 
case again a considerable section of steel, namely 974 sq. in., 
has been rendered necessary in the upper portion of the 
beam, and in its middle. If, instead of taking for b = 6o", 
which corresponds to 15 times the thickness of the slab, I had 
taken 128", namely, the third of the span, the compression of 
the concrete would have been sufficient, and this amount of 
steel would have been economised, as in my opinion there is 
no danger in taking for a principal beam in reinforced con- 
crete the smallest of the two quantities a and b for the width 
of the slab in compression, as mentioned already at the 
beginning of my lecture. 

Posts. Scantlings 15 in. x 15 in. Height 12 ft. 

The loads to be supported by the posts are as follows : — 

Slab and superload 32' x 15' x 231 = 110,800 lbs. 

Secondary beams 5' x 14' X 63 = 4410 ,, 

Principal beam 31' x 300 = 9.300 ,, 

Dead Weight 12' x 234 = 2,808 ,, 

Total = 127,318 lbs. 

The post is reinforced by means of 4 bars 1" diameter 
=-- 3*14 sq. in., and the bars are held together by means of 
spirals or hoops - r \" diameter, not taking into account, how- 
ever, the calculation of the resistance. Under these conditions 
the post is capable of supporting, according to the proposed 
official formulae — 

P = c(A + (w-i)A : ) 

c = 600 lbs. A =(15" — 2") (15" — 2") = 169 sq. in. 
in = 15. A ; = 4 x 0785 = 3140 sq. in. 
P = 600 (169 -r 14 X 3-14) = 127,776 lbs. 



TWENTY-FIFTH MEETING, April ii, 1912 201 

The post is therefore under good conditions of stability. 

It will be noticed, however, that the proposed Rules have 
obliged me to take a larger post than required owing to the 
fact that the effective area between the bars is only allowed. 
The usual practice for the calculation of such a post would 
have been to take the total area of the concrete and the 
scantlings of the post would have been reduced to 14" x 14". 
Under these conditions the concrete would have been capable 
of carrying a load of 196 x 600 = 117,600 lbs. The steel 
would then have had to support — 

127,318 — 117,600 = 9,718 lbs., 

namely, a section of steel equal to — 

97i8 

— - — = 1 20 sq. in., 
9000 ^ ' 

namely — 

4 bars -§" = i - 22 sq. in. 

As, on the other hand, it is usual to provide that the section 
of steel shall be o - 8 per cent, of the section of the concrete, I 
have had to provide — 

o - 8 x 196 = i - 57 sq. in. 
namely — 

4 bars f ' = 176 sq. in. 

It is the latter method of calculation which practically all 
specialist designers in reinforced concrete apply to posts or 
pillars when they do not take into account the supplementary 
resistance due to the lateral binding, and, in my opinion, the 
restriction concerning the effective area between the bars 
only being utilised, should apply to those who take into 
account the resistance of transverse reinforcement. 

Most of the designers, and I myself when calculating a post 
in reinforced concrete, take into account the reduction on the 
working stress of 600 lbs. for the concrete and consequently 
of 9,000 lbs. for the steel by the application of Rankine's 
formula. This reduction, as you know, is in function of the 
ratio between the height of the pillar and its width or 
diameter. 

In conclusion, I wish to draw your attention to the following 
results which have been obtained from the calculation of a 
floor in reinforced concrete, namely, that if we are obliged to 



202 THE CONXRETE INSTITUTE 

calculate a beam fixed at both extremities with a bending 

. WL , , WL . , 
moment ot — at the supports and in the middle, we 

shall have to provide a very expensive construction, or we 
may even be faced with the practical impossibility of carrying 
out the work. 

I am aware of the fact that it would be possible to obviate 
the difficulties which I have mentioned, by providing for the 
beams supported by pillars in reinforced concrete, gussets or 
brackets forming cantilevers, calculated as such, which 
would support at their extremities the beam itself. 

It remains to be seen, of course, if this manner of dealing 
with the question would be allowed by the Official Rules which 
are now in preparation, and I fear that even if a specialist 
applies this method, the official controller will oblige him to 
provide at the points of support of the beam at the extremity 

W L 

of the bracket or cantilever, a bending moment of - - 

& 12 

which would have the effect of bringing us back again to 

the case which I have already dealt with, with the exception 

that the span of the beam would be reduced to the portion 

measured between the extremities of the brackets supporting 

the beam. 

I would simply draw your attention to the fact that in this 

case the cantilever itself could no longer be considered as a 

cantilever, on account of the influence of the moment of 

WL 

at its point ot junction with the beam. 

Concerning the posts, the numerical example which I have 
given shows that the formula which might be imposed is 
really exaggerated, when the design does not take into 
account the lateral resistance of the binding! 

Finally, I am of opinion that Regulations framed for the 
purpose of becoming official and legal should not impose 
formulae, but only principles enabling formulae to be 
established, or, in any case, if formulae are given, I am of 
opinion that these should be given as examples of what will 
be required, but that these particular formulae alone should 
not actually be imposed. 

For instance, in the discussion which I have put before 
you at the beginning of my lecture concerning formulae 
which might possibly be adopted officially, I have mentioned 
formulae for the determination of the position of the neutral 
axis in a slab and in a beam. Xow these formulae, which 
are applicable in most cases, cannot be applied in certain 



TWENTY-FIFTH MEETING, April ii, 1912 203 

special cases, as I have had the opportunity of showing 
you. 

It appears obvious to me that an engineer or architect who 
may be called upon to apply Regulations concerning rein- 
forced concrete should have a sufficient knowledge of the 
laws of mechanics to be able to deal with the various 
problems which he may have to study, and to oblige him to 
follow certain formuke, would practically imply that he is 
incapable of exercising proper control of any scheme or 
problem in reinforced concrete which he may have to 
consider. 

DISCUSSION 

Professor HENRY ADAMS, M.Inst.C.E., M.C.I. : 
— I think the subject of this paper is most opportune. 
With the Official Regulations looming in the near 
future, we could not possibly have had a subject more 
important to discuss than the details of these Regula- 
tions, particularly the details which have been put 
before us. There are many statements made in this 
paper. Of course, the majority we shall probably 
agree with, but some of them, I must say, 1 do not 
agree with ; others I do not follow, and therefore 
cannot say whether I agree or not. 

My first note occurs on page 184. The author 
says, " Let us now consider the continuous beams," 
and, of course, it is continuous beams that are the 
gist of the whole paper. He says, " In this case 
the moments at the supports are generally greater 

than " There is only one case, to my knowledge, 

1 2 
where that occurs naturally, and that is in the end 
span of a beam. 

Then with regard to continuity between two con- 
secutive spans. The author admits that in structural 
steelwork it is possible to obtain perfect continuity, 
that is, by the construction of the girders ; but I think 
that it is equally possible to obtain continuity between 
girders of contiguous spans in reinforced concrete. 
It is a question in the one case of the shear strength 
of the rivets and in the other case of the adhesion of 
the metal to the concrete, and, with proper designing, 
I see no reason for putting the one class of work in a 
different category from the other. 



204 THE CONCRETE INSTITUTE 

At the bottom of the page he says, "It is obvious 
that the construction in this case becomes endangered, 
and the danger is all the greater because if one of the 
beams gives way the others will give way in turn." 
That is comparing it with a railway viaduct where, if 
one arch fails, the whole series of arches must of 
necessity fail up to the stop abutment, and that is 
why a stop abutment is put in. But in the case of 
continuous beams the severance of the continuity at 
one point does not necessarily affect the safety of the 
others ; it only makes the adjacent beams equivalent 
to the end beam of a series. 

Immediately following the author says, "It is for 
this reason that in steel construction when there are 
several continuous spans. ..." I think he will find 
that it is more a question of providing for expansion 
and contraction due to changes of temperature rather 
than to any purely mechanical consideration of con- 
tinuity. 

Then, in more than one place the author says, if this 
principle is admitted in the Official Regulations the 
section of steel required will have to be calculated 
by applying a stress in the steel equal to fifteen times 
the stress in the concrete. I do not find it anywhere 
in the Regulations ; I may have overlooked it or may 
have misread it, but I do not find it there. 

In the four different methods to be compared in 
finding the width of flange of a T-beam, the third 
one which the author objects to is, I believe, likely 
to be removed from the Regulations. It is one that 
does not compare readily with the other three, as you 
will find in the example given. I think calculation 
gives about 60 in. for three of them and 36 in. for 
the one that is objected to, so that, with the author, 
I hope that one will be deleted in the final Regulations. 

Then with regard to the beams, taking into account 
part of the floor slab, my view is that in the majority 
of cases the main reinforcement is in one direction 
only in the slab, and in that direction one must not 
take it into account as the flange of a T-beam. When 
there are main beams, cross beams, and the floor 
slab, the main reinforcement of the floor slab would 
come in the direction of the main beams — that is, from 
one cross beam to the other ; and in that case the 



TWENTY-FIFTH MEETING, April ii, 1912 205 

main beams should be taken as rectangular beams, only 
the cross beams being taken as T-beams. It is not 
quite clear whether that is what the author means here. 
He says, "If we consider the principal beams, we 
find that to the compression produced by the latter we 
must add the compression due to the secondary beam." 
I do not find any case in practice where I have to 
add the compression of the two different things, but, 
as I said, I may have misunderstood what the author 
refers to. 

Again, on page 189 he refers to 15 times the stress 
in concrete for the stress in the steel, while it is con- 
stantly happening that the design is such that this ratio 
cannot be maintained. Mentioning pillars, the author 
says that the transverse reinforcement has been intro- 
duced for purely constructional reasons, only for bind- 
ing together the principal bars during the concreting 
operation. I thought one of the chief reasons for the 
transverse reinforcement was to prevent the bars from 
bulging under the vertical load. 

On page 193, the Official Regulations, it is stated, 
do not provide any formulae for the compression over 
the supports where the reverse bending moment takes 
place. That point has been referred to in the negotia- 
tions, and possibly some mention may be made of it — 
that is, if the formulae remain in, but if the formulae 
come out we shall be able to take that with the 
ordinary modes of calculation. 

With regard to pillars, the o'8 per cent, of the 
section of concrete for the steel is a good proportion, 
but it is not always possible to keep to it. There are 
other considerations that affect the diameter of the 
pillar. When you want to keep it very small you 
may have to put more than that percentage of steel, and 
if you wish to keep it the same width as the main 
beam, then it may be that less than that percentage 
of steel is required. 

The author refers to Rankine's formula, bat the 
statement that the height of the pillar and its width 
or diameter is taken into account does not refer to 
Rankine's formula ; that refers to Gordon's formula, 
and Rankine's formula is Gordon's formula with this 
modification, that instead of the least width or diameter 
being taken into account, the radius of gyration is 



206 THE CONCRETE INSTITUTE 

taken in. These are the chief points. There are many 
others which perhaps might be discussed. I have not 
gone through the formulas in detail, as on the face 
they appear to be correctly stated. I would only say 
in conclusion that, in my opinion, all the stresses in 
reinforced concrete should be calculated by the 
ordinary laws of mechanics, and that if proper pro- 
vision is made in the design it is not necessary to 
make any surplus allowance for reverse bending 
moments. (Applause.) 

Mr. R. W. VAWDREY, B.A., Assoc. M. Inst. C.E., 
M.C.I. : — I think everybody who is at all interested in 
the subject of reinforced concrete ought to heartily 
congratulate Mons. Behar on his choice of a paper. 
As was said by Professor Adams, nothing could pos- 
sibly have been of more interest at the present moment 
than the subject which he raises, but when I come to 
deal with the different points in his paper I am afraid 
I cannot altogether agree with a good many of them. 

First of all I will mention a point in which I do 
heartily agree with him — that is, that any such set of 
rules as those proposed should, in my opinion, be 
looked upon as a means of dealing quickly and con- 
veniently with difficulties that may arise. A set of 
rules such as that proposed by the London County 
Council should be used for checking for safety any 
design which is put before an authority, but if in any 
particular case a competent designer wishes not to 
evade the rules, but to go more accurately into details, 
taking into account circumstances which perhaps are 
not covered by the rules, it does appear to me essen- 
tial, if we do not wish to prevent new and progressive 
design, to allow a designer to substantiate any position 
which he wishes to take up regarding design in this 
material. This is in a very fluid condition — I mean 
that the methods of design are continually changing ; 
they have changed very considerably in the last two 
or three years — and if no allowance is made for further 
progression the conditions which obtain at this moment 
are likely to be stereotyped, which, I think, would be 
a very disastrous business for us all. If, therefore, 
under any particular conditions a competent designer 
is able to show that what he is doing is rational, and 
that he is not apparently trenching unduly on the 



TWENTY-FIFTH MEETING, April ii, 1912 207 

margin of safety, he certainly ought, in my opinion, 
to be able to be legally in a position to put his case 
before the authorities, and if he substantiates his case 
to be allowed to proceed. If these formulas are to be 
adhered to accurately in all cases, it appears to me, 
as I said before, that the whole business is stereotyped 
in its condition at this moment. That, I think, is 
Mons. Behar's view, and I agree with what he says. 

But with regard to some of the details, it appears 
to me that his paper, a good part of it at any rate, 
might be summed up into an argument against the 
use of continuity. Well, I certainly am under the 
impression that one of the chief advantages of rein- 
forced concrete is the ease with which continuity can 
be obtained. The author admits that steelwork can 
be made fully continuous. As, I think, Professor 
Adams remarked, I utterly fail to see where the greater 
difficulty in making reinforced concrete continuous 
occurs. The author appears to treat the bending 
moment over a support as one which can only be 
resisted with difficulty. I do not see the slightest 
difference myself between the resistance of a bending 
moment over a support and that in the middle of a 
beam. It appears to me just as reasonable to suggest 
that it is impossible to resist a bending moment which 
exists in the middle of a beam as it is to say that there 
is any difficulty or danger in resisting a bending 
moment over a column. If he suggests that the 
bending moment over a column might be insuffi- 
ciently guarded against, and that therefore more stress 
would be thrown on the centre of the beam, of course 
that is so ; but it is no more likely that the bending 
moment will be insufficiently resisted over a support 
than it is that the bending moment will be insuffi- 
ciently resisted in the middle of the beam, and it 
appears to me therefore that it would be just as reason- 
able to design a floor in which the whole of the bend- 
ing moment were collected at the point of support, 
and therefore taken away from the centre of the beam, 
as to design a building in which the whole of the 
bending moment were thrown on to the centre of the 
beam and little or no precaution for resisting the 
bending moment at the support was taken. That is 
to say, you could design two extreme cases, one being 

o 



203 THE CONCRETE INSTITUTE 

the case of beams in which they are all separate, the 
whole of the bending moments being taken in the 
centre of each beam ; the other extreme being that 
in which the floor is formed by a series of cantilevers 
projecting from the supports, and merely meeting with 
a little or no connection at the centre of the span. 
One method would be as reasonable as the other, and 
1 quite fail to see why one should not vary the portion 
of bending moment at the end of the supports or the 
middle with a considerable degree of latitude. The 
possibility of doing this is not in any way affected by 
the stock argument that the external moments are 
necessarily fixed by the external conditions of loading. 
That is true only when the moment of inertia of the 
beam is fixed at all points. If, as is the case with 
reinforced concrete, we can vary the moment of inertia 
of the beam at any point, we automatically change the 
moment which has to be resisted by the beam at any 
point. 

The author does not appear to lay sufficient stress, 
as far as I can see, on resisting the greatest moment 
which must occur at any point. If the floor is designed 

as he suggests, with, sav, a bending moment of at 

40 

the support and the greatest moment, whatever it is, 

in the middle of the span, if that floor is loaded 

throughout, however great the bending moment which 

has been allowed for in the centre of the span may be, 

the — — at the support will not be sufficient to resist 
40 

the bending moment which actually occurs at that 

point, and therefore cracks will take place at the 

support, and the whole load, as the author says, will 

be thrown on the middle of the span. In that case 

it will be necessary to take the bending moment at 

the middle of the span as — — , and similarly in every 

case it appears to me that the full bending moment 
which will occur at any point must be taken at that 
point. 

Of course, the more the bending moment gets 
thrown into the middle of the beam, the better it is 
for one reason, namely, that the beam can be treated 
as a T-beam in the middle of a span, whereas it can- 



TWENTY-FIFTH MEETING, April ii, 1912 209 

not be treated as a T-beam over a support, and there- 
fore, as pointed out, other provision must be made. 
But I do not at all see any objection to making that 
other provision for the bending moment at the support 
by means of brackets or haunches, or whatever you 
call them. That can usually be done quite con- 
veniently, and I do not think there is any need to 
fear such an extreme compression in steel as the author 
evidently does fear. What is the objection to putting 
in a haunch or a bracket and not treating it as a 
cantilever, but merely treating it as deepening of the 
beam, which, I believe, is quite permissible under 
the rules ? 

There is one point made by Professor Adams I 
should like to refer to, and that is, that the main beam, 
which, as a rule, is running parallel to the main slab 
reinforcement, should not be taken as a T-beam. That, 
I think, would mean a very serious loss to the science 
of reinforced concrete as a whole, if it were upheld. 
Of course, the idea is, that as there is not very much 
reinforcement as a jule running at right angles to the 
main beam, the slab is not very well tied to it, and I 
take that to be Professor Adams's reason for objecting 
to the use of a slab as the compressed portion of a 
main beam. 

PROFESSOR ADAMS : — I may say that is not the 
reason : the reason was that you have already allowed 
for the compression in the slab in the direction of the 
main beam. 

Mr. VAWDREY :— I see ; I misunderstood that 
point. Yes, I follow Professor Adams's point. At 
the same time, it is at the centre of the slab span only 
that compression approaches anything like its limit, 
and throughout the major portion, at any rate, of the 
main beam, the slab compression near the main beam 
is very slight. It is not until one gets to some little 
distance from the beam that the slab has to support 
itself entirely by means of its own tension and com- 
pression. The portion next the beam is supported by 
shear. 

I would suggest that the Rules of the London 
County Council are very fair for use, as more or less 
general rules of design, and that any difficulty such as 
those raised by the author in his paper would be fully 



2io THE CONCRETE INSTITUTE 

met if a clause were inserted in the Regulations that 
any designer who wishes to go beyond the Rules in 
any particular must satisfy the authorities that he has 
good reason for acting as he proposes to do. (Hear, 
hear.) 

If some such clause as that were added, I must say 
that, with a few exceptions, I see very little objection 
to the London County Council Rules. One objection 
in which I agree with the author of the paper is the 
fact that it does seem to me that the advantages of 
the particular form of spiral binding in columns are 
unduly magnified. Certain advantages of that par- 
ticular form may sometimes, though they do not 
always, exist, but in any case they are unduly magnified 
by the London County Council Rules. And I also 
entirely agree with the author that where no advantage 
is taken of the binding by increasing the stress on 
the concrete of a column, one ought certainly to be 
allowed to include the whole area of the column as 
the compression section. (Applause.) 

Mr. EWART S. ANDREWS, B.Sc.fEng.), M.C.I. : 
— Mr. Chairman, there are not many points that I feel 
I should like to discuss this evening, although the 
paper touches on so many important points that one 
feels it difficult not to want to deal with' a good many 
of them. I must say I hope the author will not be 
aggrieved if I do say that I feel rather disappointed 
with the paper in one way, because from the title I 
was led to expect a solution of the question as to 
what is the true bending moment of a beam in various 
degrees of fixity, and on reading the paper it seems 
to me that the principal difficulty that the author has 
is in satisfactorily getting in the amount of steel which 
his calculations show him to be necessary if he assumes 
what is commonly taken to be the bending moment at 

WL 

the fixed support, namely, the . 

This subject of fixed beams and continuous beams 
is one at which I think I might study for very 
many years and never come very much farther out 
of the wood. It is a subject which is fraught with 
difficulty. In the first place, I would like to point 
out that the argument and theory upon which this 



TWENTY-FIFTH MEETING, April ii, 1912 211 

is obtained, is based upon the assumption that 

the beam has a constant moment of inertia, and that 
assumption, of course, does not hold in the case of a 
beam in which you have the reinforcement at the 
bottom and then bent up and used over the support. 
That, in the actual case, more nearly approximates to 
the case of a fixed beam of uniform strength. In 
that case you would have the point of contra -flexure 
of the beam at one -fourth of the span, instead of at 
'2ii of the span, is it not, of the ordinary assumption? 
And that has the effect of increasing the bending 
moment at the end and bringing it up to as much as 

— ; it will have the effect of increasing the bending 

moment at the end, because it increases the effective 
length of the part which is called the cantilever part. 

In the consideration of any formulas of this kind, 
it seems to me that we want to try and get some more 
evidence upon the subject of what exactly are the 
bending moments at the fixed end of the fixed beam, 
because, if we are going to attempt to make our 
calculations to allow for a fixed end and to avoid 
the development of the cracks which must occur, if 
no reinforcement is made, then if we calculate satis- 

factorilv, say, for the , if that is the bending 

1 2 

moment, there is no reason to worry, it seems to me, 

about the — which would occur if we had cracks, 

8 
because there is no reason to suppose that the cracks 
will ever develop. I do not know whether the meeting 
is following me ; it is rather a troublesome subject to 
discuss without diagrams. 

It seems to me rather that the author has started off 
on the subject of fixed beams and discovered difficulties 
and almost grievances in the Official Regulations 
relating thereto, and has not been able to keep out 
of other difficulties and grievances which are not 
really relevant to the subject. For instance, the pillars. 
The treatment on page 193 of the paper is one which 
is of very great importance in this matter, because if 
vou are unable to make any slab allowance at the end, 
if the slab is, as it were, at the wrong end to be of 



212 THE CONCRETE INSTITUTE 

any use to you in the resisting of the compression, 
then you really have a beam in which you must have 
double reinforcement, and, as the author says, on the 
ordinary assumption where you allow for the con- 
crete in compression, you have to have very much 
more steel in the compression side than in the tension 
side. 

I have worked at this problem several times. It 
seems to me to be only reasonable that in such circum- 
stances we ought to be able to throw over the com- 
pressive resistance of the concrete altogether and 
merely consider our beam as made up of two steel 
sections which are held at a suitable distance apart 
in much the same way as Fig. 2 in the paper ; 
A, and A c will be just two steel bars which might 
form, as it were, the flanges of a plate girder or a 
Warren girder, the concrete acting as the web or 
as the diagonal. For that to be possible, of course, 
it is necessary to get cross-binding of the reinforce- 
ment to prevent the buckling effect on the compression 
side, but I think that that could easily be allowed for 
and still economy would be effected. 

I might just make one remark in regard to Professor 
Adams's speech. I did not quite follow the reason 
for the main beams being calculated as rectangular 
only, and for no slab to be allowed as part of their 
flange. It seems to me that even if we calculated for 
the compression in the slab, as it were, by itself, to 
take its own little piece of the load, when we come to 
calculate the stress on the main beams we do not 
restrict ourselves to the remaining part of the load ; 
at least, I do not think that is the intention ; we do 
not restrict ourselves just merely to the part of the 
beam which we consider as part of the slab, but we 
take the whole load as being carried by these principal 
beams so that the fact that we have already allowed a 
certain compression in the slab to take its part of the 
stress is no reason why we should not allow part of 
the slab as part of the T-beam in taking out the 
main stress for the principal beam. 

Mr. MORGAN E. YEATMAN, M.A., M.Inst .C.E., 
M.Am.Soc.C.E., M.C.I. :— I would say, first of all, 
that I heartily agree with the author's general con- 
clusion as to not being bound by formula? without 



TWENTY-FIFTH MEETING, April 11,1912 213 

any discretion, and if it is likely that formulas will be 
officially adopted it is a very good thing that we should 
have a discussion on them and see what is likely to be 
put before us. 

As regards the columns, I entirely agree with Mons. 
Behar, and I think general practice is unanimous on 
that, that where only a moderate compression, not 
exceeding 600 lbs., or perhaps some lighter load, as 
500 lbs., is allowed on the concrete, the whole section 
of the concrete is taken into consideration. When, 
on the other hand, a higher compression is allowed 
in consideration of the increased strength due to hoop- 
ing, only the section inside the hooping can be con- 
sidered ; for it is obviously the case that where such 
columns are tested to destruction the outer concrete 
scales right off by the time the inner concrete gets 
up to its maximum load. 

In the beams we face a more difficult question. 
I had occasion, at a recent discussion at the Institution 
of Civil Engineers, to protest against making too 
great an allowance for continuity. The continuity 
is there undoubtedly, but you must remember that 
the loads are not always on all the spans at the same 
time. It is rather a difficult matter, or a long matter 
at any rate, to calculate it for a large number of 
spans, but I have worked out for three spans the 
abutment loads and the maximum moments under 
different conditions. Now, in the middle span the 

maximum is -2- WL, supposing it to be of uniform 

4° 
section all through, as it is taken in most calculations, 

though this is not altogether the case in fact. 

Mr. E. FIANDER ETCHELLS :— Uniformly 
loaded ? 

Mr. YE ATM AN :— Uniformly loaded. The maxi- 
mum moment on the centre span is -^_ WL — that is. 

40 

at the centre of the centre one when it is loaded and 
the other two are unloaded. 

Mr. ETCHELLS : — That is, the live-load moment 
only, exclusive of the moment of the dead-weight 
of the beams themselves ? 

Mr. YEATMAN :— That is right ; that is for the 



214 THE COXCRETE INSTITUTE 

live -load only. Now, the maximum moment on the 

Si 
end span is — — WL ; it is a little greater than one- 
800 

tenth, and that is obtained when the two end spans are 

loaded and the middle span is unloaded. The maximum 

moment over a support is J_ YYL, which is obtained 

Oo 
when one end span and the central span are loaded 
and the other end span is unloaded. When all the spans 
are loaded, which, of course, is the case for that part 
of the load which is dead -load, the moments over the 

supports are - — . In the middle of the middle span 
10 

it is and at the maximum point on the end span 

40 r r 

2 WL 

it is . With the central span onlv loaded the 

maximum moment at the centre is -A WL. Now, 

that shows that except in the middle span you are 
liable to have moments both at the centre of the span 

and over supports slightly exceeding ; but, of 

course, as Mr. Etchells was suggesting to me, in 
all practical cases there is a unitorm dead-load, as 
well as the variable load which may or may not come 
on the span. On the ratio between those two will 
depend what the actual maximum is in any case. In 
Turneaure and Maurer's book on Reinforced Concrete 
that question is discussed, and they gave the maximum 
for two and for three spans, with, I think, the ratio 
of 2 live to 1 dead ; and, that being a usual propor- 
tion, thev show that it is not, in general, safe to 

WL 
reckon on anv less moment than and I believe 

10 ' 

the universal practice, both in France and the United 
States at any rate, is to calculate continuous beams 

in actual construction for . 

10 

AX HON. MEMBER :— At the supports? 

Mr. YE AT MAX :— Well, I am considering the 
beams as of practically uniform section. In rect- 
angular beams there is no difficulty about that, because 



TWENTY FIFTH MEETING, April ii, 1912 215 

if you put in reinforcements symmetrically naturally 
you will get the same strength at the supports and in 
the middle. When it comes to T -beams, we are 
certainly landed in a difficulty by the fact that over the 
supports we have no T to take the compression, and 
we can hardly provide one in concrete. I think the 
alternative of deepening the beam at ths support by 
a bracket is a very good one. Certainly any method 
which leads to the putting in of three times the quan- 
tity of steel in compression at the support that you 
have in tension at the middle of the span is an 
irrational one, for to use heavy steel reinforcement 
in compression at about 6,000 tons per square inch 
is not an economical way of treating the material. 
If that had to be done, it certainly would be more 
economical to sever your continuity and provide an 

ordinary beam with — ^- at the centre. 

o 

But I think every practical constructor will agree 

that, having done that, you would not have increased 

your strength by severing the continuity. It woald 

be better to leave the continuity for what it is worth, 

and in practice I do not think you will go far out 

if you provide for at the centre and carry about 

• 10 

the same amount of metal over the supports ; say, 
let half your bottom rods run through over the sup- 
ports, half of them turn up and be carried through 
at the top over your supports, and if you have any 
compression rods or top rods in the centre, carry those 
through over the supports. I think with that 
form of reinforcement, and calculating at the centre 

WL 

for , you will get a very practical and efficient 

10 

construction. 

I must say I entirely agree with Professor Adams 

as to the danger of calculating the slabs as tables to 

the main beams — that is, in the kind of construction 

where the secondary beams or joists are much closer 

together, centre to centre, than the main beams or 

girders. In that case the floor slabs span from joist 

to joist, the tension in that direction is taken by rods 

and the upper part of the floor is in compression, to 

whatever amount of compression is allowed, parallel 



216 THE COXCRETE INSTITUTE 

to the main beams and at right angles to the joists. 
Well, if you make the main beam a Tee you put 
a compressive strain on that slab, which must neces- 
sarily be added to the compressive strain which is 
on the top part of it already. In the bottom part 
of the slab there is a compression put on by the use 
of the Tee which negatives the tension that there 
would be in the bottom part of the slab, and at the 
top over the abutments it is in the opposite direction ; 
but at the centre of each small span necessarily the 
maximum compressive strain, both from action as a 
Tee beam and from action as a slab, is at the top 
extreme fibres. We find in point of fact that those 
two compressions will be added together ; therefore, 
if you are to count it as both you must allow for 
the maximum strain to be safe under the two com- 
pressions. It is the same thing as frequently happens 
in steelwork in calculating, say, the top member of a 
roof stress ; it is in compression as a member of 
the truss, and it is in tension at the bottom and in 
compression at the top as a beam between two points 
of intersection, and you must calculate the extreme 
amount of strain as the sum of the compressive strain 
from the bending and the compressive strain upon 
the member as a whole. So in our case it certainly 
is wise to be careful how you allow for the Tee in the 
main beams. Of course, in a square panelled floor, 
with the reinforcement in both directions, the same 
will apply to secondary as well as to main beams, 
but in the floor with the joists near together there is 
no danger in using the floor as a Tee to the joists, 
because the compression in one direction from the 
local bending does not impair its strength to withstand 
compression at right angles to it from the Tee action. 
But the whole thing points to the conclusion that 
the author has arrived at, that it is both difficult 
and dangerous to lay these things down by hard-and- 
fast formulae. These things must be designed by 
people who- understand them — at least, they ought to 
be. (Applause and laughter, i 

Mr. ETCHELLS :— It is a big " ought." 

THE SECRETARY (.Mr. H. KEMPTON Dyson ) 
read the following contribution from Mr. D. 
WEBSTER ROBERTSON, M.C.I. :— 



TWENTY-FIFTH MEETING, April ii, 1912 217 

Unable to attend Mr. Behar 's lecture, I am thankful 
to have been privileged to peruse his paper, which 
deals in detail with the theoretical work in reinforced 
concrete design. 

It is depressing to open book after book and find 
that the authors go accurately into the straightforward 
part of the business, developing formulas, etc., then 
dispose of vital points, such as the amount of fixity in 
a beam, with the remark that " this must be left to 
the judgment of the designer." 

Mr. Behar has made a successful attempt to treat 
the matter rationally. 

I wish, however, to put the following questions, not 
with any fault-finding motive, but they are the sort 
of questions that might arise between a specialist con- 
tractor and the authority by whom his drawings have 
to be approved : — 

(1) In the examples worked out bv Mr. Behar 

12 

has been employed for all the slabs. Does he claim 
that the outermost beams " a " are sufficiently rigid 
to give the outer slabs "fixed ends"? Should these 

slabs not be treated as " one and fixed " with -— — on 

o 

the other bearing ? 

(2) The compression ends of the slabs are stressed 
to 600 lbs. per square inch in the first instance, and 
then in conjunction with the principal beams they 
receive an additional stress of 600 lbs. Is this per- 
missible ? 

(3) The principal beams are treated as having 
" fixed ends." The fixing, therefore, must be pro- 
vided by the columns, and must produce a considerable 
bending moment, for which no provision has been 
made in the design of the columns. The beam, in 
addition to imposing a direct load of 127,318 lbs v 
subjects the column to equal and opposite thrusts, 
at a distance of about 2 ft. apart, of, roughly, 
170,000 lbs. 

Mr. HERBERT E. STEINBERG, Assoc.M. Inst. C.E., 
M.C.I. : — I should like to add my word of thanks to 
the author for the trouble he has taken in preparing 
the paper, but I should like also to dissociate myself 
almost entirelv from the statements contained therein. 






2i8 THE CONCRETE INSTITUTE 

It seems to me, first of all, desirable to clear up the 
difference between a beam with fixed ends and a con- 
tinuous beam. The author rather falls into the error 
of treating both as though they were one and the 
same thing. The question of continuous beams is 
one that can be solved with almost the same accuracy as 
the ordinary single span beam with free supports, 

having a bending moment of — ^— . The only point on 

o 

which there can be any doubt is as to whether it is 
permissible to assume the beam as having a constant 
moment of inertia. There are, however, experiments, 
chiefly German experiments, which go to prove that 
that is quite a reasonable working hypothesis, and, 
therefore, once a constant moment of inertia is adopted 
you can calculate, as one of the speakers has already 
calculated, the bending moment for a continuous beam 
of any number of spans under any condition of loading. 
The Regulations proposed by the London County 
Council lay down fairly clearly what you are to do 
with beams when loading is evenly distributed, but 
there is also the difficulty of a continuous beam in which 
the loads are applied at points of the beam and are 
not distributed uniformly throughout the length. The 
various spans of the beam may also be unequal. Occa- 
sionally one comes across a building where the columns 
stop at the first floor beam, which thus has to carry point 
loads from two columns. It is still a continuous beam, 
but it would be ridiculous to apply bending moments of 

— or WL over any factor done by guess-work. The 

only thing to do is to calculate it properly by the 
established theories for the treatment of continuous 
beams. 

With regard to beams with fixed ends, the amount of 
fixity usually depends not upon the beams, but upon 
the part of the structure which takes the end of the 
beam. For instance, if there is a sufficient height of 
brickwork above the built-in end of the beam, a 
negative bending moment, or a counter-clockwise 
bending moment, sufficient to neutralise the clockwise 
bending moment in the beam, may be developed, and 
therefore it may realise a truly fixed end, in which 
case the bending moment at the middle of the span 



TWEXTY-FIFTH MEETING. April ii, 1912 219 

WL 

will then be relieved until it becomes Even in 

24 

this case it would not be prudent to adopt , and, 

_4 
• therefore, if you really want to make the best job 
of it, and that is by taking the most pessimistic view, 
you would calculate the bending moment at the ends 
of the beam as though they were perfectly fixed, and 
you would calculate the bending moment in the middle 
of the beam as though the ends were imperfectly fixed. 
If you are in competition and you have to keep down 
the weight of steel, of course you do not do this. 
(Laughter.) In any case, however, the greatest thing 
is to realise what you are doing and why you are 

j • ■ 1 n WL WL WL 

doing it ; these figures, Zl— } have no par- 

1 2 ' 40 ' 10 r 

ticular significance, and it would be just as reasonable 

to take or or — or anvthing vou like. 

9 25 37 & 

If you must guess them, guess them anyhow, but do not 
pretend there is any theoretical justification for so 
doing. 

The London County Council propose to lay down 

a bending moment of , and as a general rule is a 

very reasonable proposal. It is not nearly so severe 
as the German Regulations, where, I believe, if you 
cannot calculate the bending moment accurately, you 

are forced to take — ^ over the support, and 

8 10 

in the span. The London County Council bending 

moments allow more latitude than that. 

There is another fundamental fallacy into which, to 
me at any rate, it appears the author has fallen, and 
one or two speakers have also seemed to imply the 
same error, viz., that by taking a bending moment 
of a certain amount at one point in a beam you thereby 
reduce the bending moment at another point in the 
beam. You can do nothing of the sort. 

The bending moment is not a thing over which you 
have any control at all ; it depends on the loading 
of the beam and the span of the beam. What you have 
to do is to try and estimate it by calculation as 



220 THE CONCRETE INSTITUTE 

accurately as possible. Because you may have deter- 
mined, in your superior wisdom, that bending moments 

in the span shall be - — , and over the support — - 

^ 12 .4° 

the actual bending moment over the support will not 

change, nor will the true bending moment in the span 

alter. If vou put in sufficient steel for , then as 

40 

the bending moment you have taken is not enough, 

the steel will be overstressed and the concrete will 

crack, and your bending moment at the middle of the 

span will become greater than you assumed. But 

that is not designing ; that is simply silliness. 

(Laughter . ) 

After all, people who are supposed to be specialists 
— I am speaking as specialist — in a few years' time 
will have to justify their existence by being more 
expert at their work than, say, an amateur designer 
taking up reinforced concrete as a sort of hobby. 

Then with respect to the author's arguments and 
calculations with regard to the factor of safety in a 
building, it does not appear to me to need any laborious 

proof that it is more safe to take — — than • 

12 40 ' 

WL WL , , , .,, , 

— =>-, — -— would be still more safe, 
o 6 

Then, again, with regard to continuity, I quite 
agree with one speaker — I really forget who it was — 
that there is no earthly reason why the bending 
moment over the supports should not be just as reliable 
as the bending moment in the centre of the span, or 
why only the bending moment over the supports should 
be subject to all the ills of bad workmanship and 
unsuitable materials, and not the bending moment at 
centre of the span also. 

One speaker gave the maximum bending moments 
for various conditions of loading on a girder of three 
spans with the ends free, and he said the bending 
moment for the dead -load which cannot change from 

span to span has a maximum of — _ in the end span, 

12-5 

YYT > th 

— - over the first support, and — _ in the centre span. 
10 40 y 



TWENTY-FIFTH MEETING, April ii, 1912 221 

Now the superload may exist on all the spans, on the 
centre span only, the end span only, or it may exist 
on the two end spans ; these four cases must therefore 
be calculated, and the worst possible bending moment 
taken from each case. When these have been added 
to the bending moments of the dead -load the work 
will have been done as accurately as possible, and 
then if the area of concrete and the reinforcement is 
calculated according to those bending moments the 
best possible job has been made of the work. 

Xow the author says, if you adopt anything like 
the above procedure, you are led into great difficulties 
with your bending moment over support, owing to 
the small area of concrete in compression, but I do 
not think you are. He suggests that to adopt Mon- 
sieur Considered method of putting spirals in the 
underside of the beam is satisfactory, but as the spiral 
reinforcement is still controlled by a patent in this 
country it cannot be universally adopted. But how is 
it that in Germany, where, as I say, the bending 

moment over the support is to be taken as — =— , and 

o 

Considered spiral patent also holds, an enormous 

amount of reinforced concrete is done annually to the 

stringent Official Regulations? If it were almost im- 

WL 
possible to design with — over the support, as the 

author suggests, it would be perfectly prohibitive with 
such a regulation as — g- 

o . 

The examples that the author gives are not chosen 
in a very practical way. He could easily have made 
his beams wider, he could easily have put gussets on 
to them, or done two or three things, and he would 
have got over his difficulties. Of course, I suppose 
he chose an example in order to make the difficulty 
obvious. 

With regard to the method of putting in spirals in 
the lower side of beams near the points of support, 
that the author apparently considers to be a good and 
satisfactory method, and, as an admirer of Mons. Con- 
sidere, the inventor and patentee of the spiral, I fully 
agree with him, but it is not essential to overcome the 
difficulty in this way. It may make the best job of 



222 THE CONCRETE INSTITUTE 

it, but there are other, if less perfect, solutions to the 
problem. 

Then, there was a point which has been raised by 
various speakers with respect to the compression of 
the concrete in the slab. Apart from the fact that the 
compression in the slab due to the bending moment 
in the slab exists only for about one-third of the way 
down, there is also another fact, viz., that quite apart 
from how you consider it — you can consider it how 
you like — immediately a slab passes over the beam 
it is prevented from deflecting in the direction of its 
span, and, therefore, there is no bending moment and 
no compression in the slab at that point due to its 
own action, and this effect extends for a considerable 
area on either side of the beam, so that even, although 
on paper the arrangement of the beam may look as 
though the slab was doubly compressed, in practice 
it cannot possibly be so. 

There is also a statement that the French have 
different Regulations for secondary beams from those 
which they insist on for main beams. That is on 
page i 88. I am not at all sure that that is correct. 

I have one or two points in which I agree with the 
author, and first with regard to columns. I think that 
it is quite reasonable that the cover of concrete should 
be recognised as contributing to the strength of the 
columns. Of course, if you enhance the value of what 
you might call the " basis stress " of the concrete by 
putting either a series of ties closely together, or by 
a spiral, you put a larger stress on your concrete core 
than on the plain concrete. But, nevertheless, I think 
that the large area outside the round or square core 
might be taken at, say, 600 lbs. per square inch. I 
see no harm in that at all. The cover inevitably con- 
tributes to the strength of the column, and there are 
numbers of experiments to prove that the more you 
reinforce the core, the higher you raise the point at 
which the cover begins to peel off, so that there is 
really no reason against assuming that the cover of the 
concrete outside the core does work at something or 
other ; I think, therefore, 600 lbs. or 700 lbs., the 
ordinarv basis stress on the concrete, might be taken 
as the figure. 

Then, on page 202, there is a paragraph or two about 



TWENTY-FIFTH MEETING, April ii, 191 2 223 

the cantilevering action of the beam. Personally, I 
do not agree with that way of looking at the problem at 
all. If you put in gussets in the beam they are still 
part of the beam, and although there is undoubtedly 
some inaccuracy in assuming a constant moment of 
inertia, yet it is small compared with the other assump- 
tions one is forced to make. If, therefore, you 
recognise the beam as being continuous, and if you 
assume tihat it has a constant moment, and you calculate 
your bending moment for every possible contingency 
of loading as accurately as you can, I do not care 
whether the Regulations as laid down anticipate your 
particular case or not, but I do not think you would 
have any difficulty in getting your drawings passed by 
the authorities. But if, on the other hand, you desire 

to take bending moments much less than , without 

12 

any theoretical justification, then I think very rightly 

the Regulations will stand in your way. 

Mr. E. FIANDER ETCHELLS, F.Phys.Soc, 
M.Math.A., A.M.I.Mech.E., M.C.I. :— I have pleasure 
in moving a vote of thanks to the author. The 
adoption of reinforced concrete work depends upon 
two factors — first, its cost, and, second, its safety, and 
we should seek a reasonable compromise between these 
two divergent ideals — i.e, we want the greatest stability 
with the least cost. 

I have heard the doctrine that reinforced concrete 
is subject to the laws of a super statics of a recondite 
character, and that reinforced concrete construction is 
one of the occult sciences, whose laws transcend the 
laws of physics and of ordinary matter. 

But now that phase is passing away, even among 
the specialists themselves. The specialists have tried 
to lift reinforced concrete out of its cradle of empiri- 
cism and put it on a more settled basis. 

The British specialists have recommended that in 
all important cases the bending moments under all 
possible conditions of loading should be accurately 
determined, and the beams designed at each point 
in their length to resist the maximum bending moment 
which may occur at such point, but that for small 
ordinary floors a sufficiently accurate result would be 



224 THE COXXRETE INSTITUTE 

obtained bv using a bending moment of -, both 

12 

over the support and in the centre of the span for 
continuous beams. 

The Second Report of the Joint Committee of the 
Royal Institute of British Architects recommended that 
the bending moments should be calculated on ordinary 
statical principles, and the beams or slabs designed 
and reinforced to resist these moments. Where the 
maximum bending moments in beams or floor slabs 
continuous over three or more equal spans, and under 
uniformly distributed loads, were not determined by 
exact calculation the bending moments should not be 

taken less than -4- at the centre of the span 

12 

an d _ at the intermediate supports. 

This raised the question as to what the ordinary 

statical principles were. Would it be in accordance 

with the ordinarv statical principles if, knowing that 

WL 
there is a bending moment of at the support, we 

12 

, • , , ( WL WL , 

only provided for or ? 

40 24 

This report speaks of exact calculations, but the 
most exact calculations we have are based principally on 
Clapeyron's famous theorem of three moments, which 
was first published in Comptes Rendus about 1857. 
It is based on several assumptions, one of them being 
the constancy of the inertia moment. To solve the 
problem it is necessary to employ the double integra- 
tion of a differential equation, and though you work 
out the numerical result to the furthest decimal, what 
is the good of the result if there is a basic assump- 
tion that is far from the truth ? 

Speaking of steelwork, where there is admittedly 
a greater degree of continuity, in general it may be 
said that the bending moments at the supports next 
the end are always greatest, and are there about 

, , and near the centre supports thev are nearly 

10 

uniform at about 

12 



TWENTY-FIFTH MEETING, April ii, 1912 225 

Since the Draft Regulations were written we have 
from America, the land of up-to-dateness, two further 
Reports, or Codes, and they both fully support the 
Draft Regulations in respect of the bending moments. 
The Joint Committee representing the American 
Society of Civil Engineers and the principal scientific 
institutions over there recommend, " That for beams 
the bending moment at centre and at support for 

WL 

interior spans should be taken at , for both dead- 

and live -loads." Then, again, it goes on to say, 

" For spans of unusual length more exact calculations 

should be made. Special consideration is also required 

in the case of concentrated loads. Even if the centre 

of the span is designed for a greater bending moment 

than is called for by the previous paragraph, the 

negative moment at the support should not be taken 

at less than the values there given." Furthermore, 

it is stated that, " In the design of Tee beams acting 

as continuous beams, due consideration should be given 

to the compressive stresses at the support." 

The New York Code which came into force this 

year states that " The bending moments at centre 

and support for beams or girders continuous over 

WL 
two or more supports shall be taken at -,■ " The 

Regulations of the Royal Prussian Ministry say that 
" If conditions at support produce restraint and con- 
tinuity of slabs and beams, the bending moments which 
appear at those points must have reinforcement placed 
near the upper stressed surface in proportion to the 
bearing area. 

If a continuous beam or slab cannot be computed, 
or, in regard to the latter, if no restraint is certain 
at a beam or wall, then, with equal panels and 
uniformly distributed load, the moment is not to be 

taken less than — _— over the supports or than at 

8 10 

the centre of panels." 

It has been said that the Draft Regulations under 
discussion would prohibit the use of reinforced con- 
crete, that it would kill the trade. In reply, I ask 
whether the reinforced concrete trade is dead in 
Germany ? Is it dead throughout the United States ? 



226 THE CONCRETE INSTITUTE 

With regard to the breadth of Tee beams, we are 
also told that the Regulations will militate against the 
use of reinforced concrete, but that does not seem 
probable when we bear in mind that the particular 
Regulation referred to was suggested by the Com- 
mittee of Specialists themselves. They unanimously, 
and on their own initiative, recommended that the 
width of the area under compression in Tee beams 
should not be greater than fifteen times the thickness 
of the slab or flange. 

The New York Code, revised this year, states that 
the breadth of the compression flange of the Tee beam 
should not exceed twelve times the thickness of the 
slab plus the breadth of the rib. Therefore it would 
appear that the regulation under discussion of fifteen 
times the thickness, as recommended by the specialists 
themselves, is apparently good practice, and also more 
or less accords with international practice. 

Take the ratio of the breadth of the flange to the 
span of the beam, the Regulations of the Royal Prus- 
sian Ministry say you shall only take one -sixth of the 
span as the breadth of the flange. The New York 
Revised Code gives the same figure. The American 
Joint Committee are a little more lenient ; they say 
you may take one -fourth of the span. 

The London County Council Regulations allow twice 
the width of the Prussian, twice the width of the New 
York, and permit a breadth of one-third of the span. 
The complaints seem to arise irrespective of the 
weight of evidence. 

With regard to formulae generally, it appears to me 
that formulae represent the engineer's shorthand, and 
are a symbolic method of representing the truth, and 
so long as we do not mistake the symbol for the truth 
itself all will be well. 

Formulae, after all, are merely epigrammatic methods 
of stating the laws of science. 

It has been well said that " in physics the memory 
disburdens itself of its cumbrous catalogue of par- 
ticulars and carries centuries of observation in a single 
formula." 

The Regulations are given in words or in formulae, 
whichever are the most convenient. 

Equations are vitally necessary, and they are neces- 



TWENTY-FIFTH MEETING, April ii, 1912 227 

sary to ensure that the stresses are within the limits 
set by the Regulations. Every one has known that 
many times people have made the assertion that the 
stresses were under 600 lbs. per square inch, after 
having made their own assumption about the bending 
moment. You know you have only to make the 
denominator in the bending moment equation what 
you like and you will get yoar stresses low enough to 
comply with any Regulations. (Applause and 
laughter. ) 

Air. Behar stated that he was of opinion that regula- 
tions framed for the purpose of becoming official and 
legal should not impose formulae, but only principles 
enabling formulae to be established ; or, in any case, if 
formulae was given, he was of opinion that these should 
be given as examples of what would be required, but 
that these particular formulae alone should not actually 
be imposed. 

1 suggest that if principles only were given very 
few architects, surveyors, magistrates, or builders would 
be able to truly affirm whether the statical require- 
ments of the regulations had been complied with. 
If merely principles were laid down we would require 
to be Rankines, Clapeyrons, and Eulers as well to 
convert the basic principles into a form that would be 
suited for the practical work of design. 

Basic principles might please the professors of 
engineering, but would they help the busy builder 
who had to put up buildings in a hurry ? 

Mr. Behar stated that he was of opinion that an 
engineer or architect who may be called upon to apply 
regulations concerning reinforced concrete should have 
a sufficient knowledge of the laws of mechanics to 
be able to deal with the various problems which he 
may have to study, and to oblige him to follow certain 
formulae would practically imply that he was incapable 
of exercising proper control of any scheme or problem 
in reinforced concrete which he may have to consider. 

I hold that such a conclusion is unjustified. The 
architects and engineers were consulted before any 
Regulations were sent forward to the allowing authority. 
Then, since the architects and engineers were con- 
sulted before the Regulations were made, such 
consultation effectively admits their competency not 



228 THE CONCRETE INSTITUTE 

only to carry out the works, but to criticise the draft 
and to participate in the work of law-making. 

I maintain also that it would be easier to see whether 
a particular design complied with certain stresses than 
it would be for the building authority, or any officers 
of the building authority, to discriminate as to who 
were competent and who were not. That would be 
a very arduous task and a very difficult task, and one 
open to very grave abuses ; and it is much easier to 
judge a plan than to judge a man. 

Mr. BEHAR then made some remarks in reply to 
the discussion, but as time did not permit of a full 
reply he has sent the following contribution in 
writing : — 

Professor Adams has stated that the moment at the 
point of support in the case of continuous beams is not 

alwavs greater than — . This assertion is correct, 

' 12 

but what I have endeavoured to point out to you in 

my lecture is, that in reinforced concrete, by reason 

of the assumptions which we have to make, to apply the 

formulas of continuity we have to apply at all the points 

of support the greatest bending moment which we 

have found for one of the supports, and this moment is 

always greater than — . 

I 2 

In order to throw more light on this subject let us 
consider a reinforced concrete floor, in which we have 
to study a series of twelve continuous beams. Pro- 
fessor Adams, I suppose, will agree that it would not 
be wise to apply the continuity to the twelve spans, and 
I take it that he will require the latter to be divided 
into a certain number of sections — for instance, three 
sections of four spans each, the continuity being applied 
only to each of these particular sections. We have, 
therefore, a section of four beams resting on five points 
of support. 

In order that we may be able to apply the theorem 
of Chapeyron we must assume that the moments at 
points of support i and 5 are equal to o, and if we are 
dealing with equal spans and equal distributed loads 
we shall have, for the other supports, moments equal 
to— 



TWENTY-FIFTH MEETING, April u, 1912 229 

B 2 = B 4 = - lWL >-^t. 

* 28 12 

B 3 =_ ;WL<-WL. 

* 28 12 

On thirteen points of support we have, by assump- 
tion, the following : — 

Supports 1, 5, 9 ... ... Morrtents = o. 

Supports 2, 4, 6, 8, 10, 12 Moments of — -4; WL. 

2o 

Supports 3, 7, 1 1 ... ... Moments °f"~^^^ - 

Owing to the peculiar nature of reinforced concrete 
constructions, in which the supports of the beams are 
constituted by other beams or posts in the same 
material, it is obvious that the free supports do not 
exist, and I take it that Professor Adams would not 
consider the points of support 1, 5, and 9 without 
reinforcement to resist negative bending moments, the 
value of which, however, is in reality unknown. More- 
over, we may take as the starting-point of a section 
of four spans any particular point of support, so that 
we would find ourselves obliged, by measure of pre- 
caution, to assume that the greatest moment found 
for one of the supports should be applied to all the 
supports. 

If the total length of the twelve spans had been 

divided up into groups of three beams the greatest 

,^ u u WL. T 
moments on the supports would have been — > l 

think, therefore, I was right in saying that in con- 
tinuous beams it is necessary to provide at the points 

r 1 WL 

of support a moment greater than — .. 

1 2 
Professor Adams is of opinion that in these beams 
the compression of the slab must not be taken into 
consideration, for the reasons which he has given. 
Mr. Yawdrey has answered upon this point. I would 
take the opportunity, however, of the question raised 
by Professor Adams to explain more clearly my method 
of reasoning concerning this matter (pages 187 and 188 
of my paper), which has appeared rather obscure, to 



230 THE CONCRETE INSTITUTE 

some of the members of the audience, amongst others 
to Mr. Etchells, who is fathering the Rules which are 
at present under discussion. 

Let us consider a slab supported by secondary beams 
in reinforced concrete (Fig. i ), and let us examine 
a square portion of this slab having i sq. in. in area, 
of which the centre is situated at the point of inter- 
section of the two axes passing at the middle of 
the span of the slab and at the middle of the 
span of the secondary beam. The upper face of the 
element A under consideration will be submitted to 
an effort of compression F, owing to the flexion of 
the slab. This effort of compression will be normal 
to the direction of the secondary beam, and owing 
to the flexion of the secondary beam the element A 
will also be subjected to an effort of compression 
directed in a parallel direction to the secondary beam. 
Therefore the resultant force R of these two forces 
F and F 1 might be greater than 600 lbs. per square 
inch, inasmuch as the force F is already itself almost 
equal to 600 lbs. if we assume that the slab is free 
to bend on the entire span, between the secondary 
beams, without being influenced in any way by the 
flexion of a portion of this slab working with the 
secondary beams, which, in fact, would be exaggerated. 

Let us now examine the compression of the slab 
when the principal beam comes into play (Fig. 2). 
Let us consider an element B having 1 sq. in. in area 
and situated on the upper face of the slab at the 
middle of the span of the secondary beam, which is 
nearest to the middle of the principal beam. 

This element B receives a compression F, coming 
from the flexion of the secondary beam, and directed 
normally to the main beam. This element is not 
influenced in any way by the slab, because in reality 
the entire area b is deflected with the beam. From 
the main beam the element receives a compression F 1 , 
acting in a parallel direction to the principal beam. 
The resultant R of the two forces F and F 1 will be 
generally less than 600 lbs. per square inch, because 
the forces F and F 1 will be usually much less than 
600 lbs. per square inch, if the whole area 1 of the 
secondary beam and the whole area b of the main 
beam are taken in consideration. 



TWENTY-FIFTH MEETING, April ii, 1912 231 










fl 1 


1 
1 


\> 





^ 

^ 

^ 




— (--- 



V 



1 



v> , 



t-T 



•ft 



232 THE CONCRETE INSTITUTE 

I conclude by what precedes that, for the principal 
beams, the Regulations should be less stringent in the 
determination of the width b to be taken into 
account in the calculations. 

Mr. Yawdrey holds the same opinion as Professor 
Adams in saying that the formulae of the Regulations 
should not be imposed, but should simply be set forth 
as a guide. I am entirely of their opinion on this 
point, as shown by the concluding remarks of my 
paper. 

Mr. Yawdrey also states that he does not see why 
continuity should not be applied to reinforced con- 
crete. I do not say that the method of continuity 
should not be applied. I have simply drawn your 
attention to the fact that in my opinion the method 
of continuity is farther from the reality in reinforced 
concrete than in steel construction, unless we assume 
at all the points of support the greatest bending 
moment found for one of these points, as I have 
pointed out in my answer to Professor Adams. Con- 
tinuity finds a better application in bridge-work, 
especially when the points of support of the beams 
are constituted by a series of piers, the ends of the 
bridge being supported by masonry abutments. 

We must not lose sight of the fact that the theorem 
of Clapeyron is based on three fundamental assump- 
tions :— 

(a) That the moment of inertia of any section 

of the beams is constant. 

( b ) That all the points of support are on the 

same level. 

(c) That the points of support are simply repre- 

sented by lines, or, in other words, a 
sharp edge at each point of support. 

The first of these conditions is never ensured in 
reinforced concrete beams. 

Concerning the third of these conditions, although 
this might be assumed for secondary beams resting 
upon principal beams, I fail to see how this could be 
attained when the beams are supported by pillars, the 
scantlings of which in certain cases reach 24 in., 
especially when these posts are supporting other posts 
above, transmitting heavy loads. In such cases we 



TWENTY-FIFTH MEETING, April ii, 1912 233 

WT 

would have a perfect fixation, and — could be 

1 2 

imposed with in the middle of the beam — that is, 

24 

if we wish to be in perfect accordance with the laws 

of mechanics. I am not of opinion, however, that this 

should be done, as this would lead us to have an 

insufficient amount of steel in the middle of the beam, 

which would cause the latter to be weak if by any 

chance the amount of fixture at the points of support 

had been overestimated. 

Concerning the assumption (b), I would simply say 
that it may happen that in floors supported by a 
certain number of pillars some of the latter may sink 
more than others, owing to defective foundations, and 
if this were to happen it is possible that the span of 
one of the beams instead of being 1 might become 
2X1, owing to the sinking of one of the inter- 
mediate supports. Unequal sinking of any pillar is, 
however, less likely to happen in reinforced concrete 
than in any other material, owing to the monolithic 
nature of the construction. 

I will deal with Mr. Steinberg's argument against 

the points of support with a moment of — at the 

40 

same time as I answer Mr. Etchells on this point. 
Concerning the gussets in the beams, Mr. Steinberg 
is unwilling to assume that these should be considered 
as cantilevers, but simply as an increased height of the 
beam at the points of support. I hold the opinion, 
on the contrary, that if the gussets are properly rein- 
forced we may treat these as cantilevers without 
endangering the construction, and this has the advan- 
tage of bringing about an economy in the construction. 
In further reply to Mr. oteinberg, he states that 

„, . f WL , WL WL , WL 

the moments of — and or — and 

40 10 24 12 

are only guesses — namely, that we assume one or the 
other at the supports or at the middle of the beam,, 
and that the other corresponding moment is deter- 
mined by calculation. These, however, are not guesses, 
but assumptions which are made in the same manner 
as those which he himself would have to make in 
calculating continuous beams when he assumes, in order 



234 THE CONCRETE INSTITUTE 

to apply the theorem of Clapeyron, the various hypo- 
theses which I have mentioned in my answers above. 

Mr. Steinberg says that all we have to do is to 
increase the width and height of a beam or secondary 
beam at the point of support in order to take up the 
compressive resistance at these points. He probably 
forgets that floors in reinforced concrete depend upon 
the requirements of architects more than upon the 
engineer designing the scheme. Very often the height 
and the width of the beams have been fixed to satisfy 
other conditions which have nothing to do with the 
calculations. What would he do in this case to resist 
high compressions with a stress of steel limited to 
6,000 lbs., or even to 4,000 lbs. only, per square inch? 

Mr. Etchells has told us in the discussion of my 
paper that the Rules of the London County Council 

specify — - — at the supports, whereas the Prussian 
Regulations stipulate — — — . 

o 

I should like to know how those engineers who 
have to apply these Regulations overcome the difficulty 
of the compression of the points of support, which 
I have mentioned above. Mr. Etchells, however, has 
forgotten to tell us that these same Prussian Regula- 
tions authorise a working stress of the concrete in 
tension, and attribute to the latter a stress equal, to 
two -thirds of the crushing stress of the concrete in 
tension, and as they assume that the resistance to 
crushing in tension is equal to 228 lbs. per square inch, 
the application of these Rules would lead us to have 
a width b of the slab working in tension, at the same 
time as the beams at the points of support, at an 
average stress of 120 lbs. to 140 lbs. per square inch. 
On this account the bars in tension at the points of 
support will represent a section of steel certainly much 
less than the section which we obtain by the application 

of the formula — of the proposed Regulations of 

the London County Council. 

Concerning the compression at the points of support 
we do not know whether the Prussian Regulations 
stipulate that the section of steel shall be calculated by 
applying to the latter fifteen times the working stress 



TWENTY-FIFTH MEETING, April ii, 1912 235 

of the concrete applied to the centre of gravity of 
the bars, whereas the proposed Regulations of the 
London County Council actually adopt this view. 

To conclude my answer to Mr. Etchells's remarks, 
the aim of my paper has not been to try to urge that 
certain methods of calculating a moment for a beam 
in reinforced concrete should be adopted, in preference 
to any other method, but to show that a greater safety 
could be obtained by providing at the middle of a 

beam a bending moment higher than , or at least 

12 

equal to this value, and to show if the method of cal- 
culating beams as continuous may be sometimes dan- 
gerous, it is precisely because by this method one is 
led to provide, in certain cases at the middle, bending 

moments which are smaller than , whereas at the 

12 

points of support, if the designer of a scheme pro- 
vides reverse bending moments less than — , the 

12 

danger is not so great on account of the table b of 
the slab, which is working in tension at the same time 
as the beam. In fact, to a certain extent, this view is 
confirmed by Mr. Etchells himself, since he would 
have no hesitation in considering a beam in rein- 
forced concrete as being free upon its supports, even 
if it were resting upon another beam or a pillar, on 
condition that the bending moment at the middle 

should be taken equal to ., but it is to be noticed 

o 

that for greater safety he advises in this case to pro- 
vide at the points of support a few small bars in the 
upper portion of the beam. 

It would appear to me that, if Mr. Etchells is willing 
to accept this method, he does not differ very much 
in opinion from those who think, like myself, that 

the safety of a beam is not impaired by adopting 

in the middle and — at the supports, or any other 

40 

similar assumption, on condition, of course, that as 

far as the middle of the beam is concerned, we always 

u WL 
remain above . 

1 2 



236 THE CONCRETE INSTITUTE 

To terminate the discussion, I wish to explain the 
formula which I attribute to Rankine and which I 
mentioned at 'the end of my paper. This is also in 
answer to Professor Adams's remarks. 

This formula is — 




in which c 1 is the stress of the material of the post 
in order to take into account column flexure, a is a 

numerical co-efficient equal to — — , c is the maximum 

oE 

stress of the material in compression, namely, 600 lbs. 

for the concrete, h is the height of the post, A the 

section of the post, and I its moment of inertia. 

We have — 



Cl ~ 


c 

~~ 8E = 


c 




16,000,000 


A is equal to b 2 






I is equal to — 
1 2 







If we neglect the steel bars, which we have a right 
to do since we are considering the stress of the con- 
crete, by substituting in the preceding equation we 
have — 



or else — 



12c h 2 

1 + ~Z x 71 

16,000,000 b 2 



hV 

1 + - " x 7"5 — It 

10,000,000 ' \o 



This formula applied to the various values of _ 

allows us to calculate the working stress c 1 for - " 
For instance, we would have — 

c, = —z = S46 lbs. 

1 + 0-00006 x 7 # 5 x 223 



TWENTY-FIFTH MEETING, April ii, 1912 237 

In mv opinion, when the transverse reinforcement 
is not taken into account in the calculation of a post, 
the above formula could be adopted, in order to make 
the construction safer, instead of the formula, given 
in the Rules of the R.I.B.A. or in the proposed Rules 
of the London County Council. 

I regret that, owing to the length of the debate, it 
has not been possible for me to answer individually 
the remarks of the other members. 

THE CHAIRMAN (Sir HENRY Tanner), in closing 
the meeting, said : — Monsieur Behar fell into a slight 
error with regard to Wimpole Street and Manor 
Gardens, Holloway. Mr. Wager was the architect 
of these two buildings, I had nothing to do with them. 

The meeting then terminated. 

Mr. ETCHELLS has forwarded the following con- 
tribution to the discussion, as the time did not permit 
of a full discussion of all the points involved : — 

SIR, — The pressure of time and the lateness of the 
hour prevented the full development of my arguments 
in respect of the true bending moments of beams. The 
verbal discussion represents but a part of the case. 

Mr. Behar, in the course of his remarks, stated that 
" if the total length of the twelve spans had been 
divided up into groups of three beams the greatest 

moments on the supports would have been - — — and 

that in continuous beams it is necessary to provide at 

the points of support a moment greater than - - — ." 

I find myself in agreement with him here, because 
here he is in agreement with the laws of mathematics 
and mechanics, on which I take my stand. 

Again, I should like to support Mr. Behar 's reply 
when he stated that by reason of the assumptions which 
we have to make in respect of continuity We have to 
apply at all the points of support the greatest 
bending moment which we have found for one of 
the supports, and this moment is always greater than 

WL 

As to the strength of brackets, it should 

be sufficient for me to say that I see no objection to 



238 THE CONCRETE INSTITUTE 

them, provided that the restraining couple is sufficient 
and constant — i.e., the restraining should not depend 
upon the accidental presence or absence of a load on 
some adjoining bay. Mr. Behar draws my attention 
to the Prussian Regulations and their reference to 
tension in the concrete. In reply, I should like to 
point out that the particular question under discus- 
sion is the true bending moment of beams, and not 
the hypothetical resistance moments ; but Mr. Behar 
does well to point out that there are qualifications and 
modifying conditions accompanying this most stringent 

WL 

regulation as to a bending moment of — — ^— over 

WL 

a support in lieu of the more usual — . 

Might I now draw his attention to a further 
fact in respect of the stringent Prussian Code — viz., 
that when the tension in the concrete is allowed the 
stress . on the steel would appear to be limited to 
2,400 lbs. per square inch instead of the t 6,000 
common to British practice. How is this for 
stringency ? To draw my attention to the omission 
affords me an opportunity of stating the other qualifica- 
tions. Prussian Code, Chapter D, Section 16, Sub- 
section 2 states inter alia that the tensile stress is 
not to be assumed greater than one-tenth of the ulti- 
mate compressive stress. Let us take a British concrete 
with an ultimate compressive strength of 2,400 lbs. 
per square inch at three months. The ultimate tensile 
strength would then be 2,400 10= 240 lbs. per square 
inch. Subsection 2 of Section 16 states that two- 
thirds of the tensile strength may be allowed. In 
our case f of 240 would give 160 lbs. tension. 
Chapter C, Section 15, Subsection 1 (of the Prussian 
Code) gives the modular ratio as 15. Therefore the 
stress on the tensile reinforcement embedded in 
concrete in tension would be 15 X 160 = 2,400 lbs. 
per square inch, not 16,000. I thank Mr. Behar for 
affording me the opportunity of showing the real 
stringency of this particular Code. In the foregoing I 
have taken a British concrete, but if I took the German 
concrete the stress in the steel would be lower still. 

Now, may I add qualification to qualification and 
point out that Mr. Behar's remarks appear to assume 



TWENTY-FIFTH MEETING, April ii, 1912 239 

that the Prussians always allow the concrete to take 
tensile stresses, whilst the fact is that Section 15, Sub- 
section 2 states that " The stresses in any section of 
a body under flexure are to be computed on the 
assumption that the reinforcement carries all the 
tension. Tensile stresses on the concrete are only 
allowed in buildings or members exposed to the 
weather, to dampness, to smoke, gases, and similar 
deleterious influences, where it must be shown that 
cracks will not occur from the tensile stress to which 
the concrete is subjected. I now, sir, deliberately 
reaffirm that the Prussian Code is more stringent than 
British practice. I refer you to the Codes themselves. 
I know the objections and the qualifications and the 
limitations ; but when I present a precis of a foreign 
code that precis is a true mirror of the original, 
although every detail may not be elaborated. The 
suggestion has been made that for a uniformly dis- 
tributed load the bending moment at the one support 
plus the bending moment at the centre should equal 
WL 
— q— . It is suggested that anything contrary to this 

is contrary to the laws of mechanics. Now, the laws 
of mechanics is a very wide term. It is quite true 
that at the particular second when the end moment is 

WL , , L WL , 

— - — the centre moment is probably only about — — , but 

the laws of mechanics deal with moving loads, with 
rolling loads, and central bays loaded and adjoining 
bays unloaded. The laws of mechanics deal with 
diagrams of maximum bending moment for any 
position of a moving load. They deal with problems 
of an unfavourable disposition of a static load. They 
deal with questions of an envelope of bending-moment 
diagrams. They deal with influence lines, a method 
of dealing with maximum moments which is used by 
progressive railway engineers, but is almost unheard of 
among builders. The laws of mechanics cover some- 
thing more than the static and constant bending moment 
of a uniform load glued to a beam for ever. Let my 
friend the busy builder put his centre moments at 
not less than his end moments. Let his end moments 
be arrived at by the simplest theory, and then he can 
leave all this erudition to the professors ; and " he 
will have built better than he knew." 

Q 



TWENTY-SIXTH ORDINARY GENERAL 
MEETING 

Thursday, April 25, 19 12 

THE TWENTY -SIXTH ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296, Vauxhall 
Bridge Road, London, S.W., on Thursday, April 25, 
191 2, at 8 p.m., 

Professor HENRY ADAMS, M.Inst.C.E., M.I. 
Mech.E., M.C.I., etc., in the Chair. 

MR. A. ALBAN H. SCOTT, M.S.A., M.C.I. (Hon. 
Secretary of Tests Standing Committee) : — In the un- 
avoidable absence of Mr. Kirkaldy, the Chairman of 
this Committee, I have pleasure in putting before 
you the Interim Report of the Tests Standing Com- 
mittee on the " Testing of Concrete, Reinforced Con- 
crete, and Materials Employed Therein " (which report 
was published on pp. 265-70 of Volume III. of the 
Transactions) and the following further report : — 

REPORT OF THE TESTS STANDING COMMIT- 
TEE ON THE TESTING OF REINFORCED 
CONCRETE STRUCTURES ON COMPLE- 
TION. 

It is frequently specified that test loads should be applied 
to finished structures of reinforced concrete shortly after 
completion. It should be recognised, however, that such 
tests should in no wise reduce the care to be exercised in the 
supervision of the work by those responsible. Since the 
test loads are generally applied only to specific parts of the 
work, such tests do not necessarily prove that the work has 
been properly executed either in whole or in part. 

240 



TWENTY-SIXTH MEETING, April 25, 1912 241 

The test load should not be applied to any part until the 
expiry of 90 days from the last day of laying the concrete. 

The deflection of beams under a test equal to the full 
working load for which the beams were designed should not 
exceed i/ioooth of the span. 

In order to impose the full load upon a floor or roof beam 
under test the two bays of floor or roof adjoining require to 
be loaded all over, otherwise a considerable portion of the 
load is transmitted to the adjoining beams and the full load 
does not come upon the beam under test. 

Not more than the superimposed load for which the beam 
has been designed, plus 50 per cent., should be applied as a 
test load. 

When test loads are applied the materials used for loading 
should be put on in such a manner that no arching action 
whatever can take place, otherwise incorrect results will be 
obtained. 

If systematic and thorough supervision be given by the 
professional adviser during course of construction the appli- 
cation of test loads to the finished structure is not so 
necessary. 

Test cubes, if kept in an even temperature, which should 
be the same as that specified for cement briquettes, form a 
means of gauging under standard conditions the resistance 
to thrusting, and cubes kept in the open air will give the 
values for the concrete in actual practice. The results of 
these two sets of tests will be helpful in determining at what 
age the work is strong enough to sustain the loads. 

I think I am right in saying that this Committee 
has held practically more meetings than any of the 
other Committees of this Institute, considering the 
time it has been in active operation. 

DISCUSSION. 

Mr. MORGAN E. YEATMAN, M.A., M.Inst.C.E., 
M.Am.Soc.C.E., M.C.I. : — I have not much to con- 
tribute, as I have not had an opportunity of making 
a study of the Report till I came into the room, and 
I have not gone specially into the question of testing. 
But there are many points which it will be valuable 
to have discussion upon. I know the question of the 
proportion of water has always been a difficulty, and 
I think the Committee are probably wise in concluding 
that it is impossible to prescribe numerically the pro- 



242 THE CONCRETE INSTITUTE 

portion of water to be used. It must be judged by 
the conditions and the results in mixing. 

In the question of the grading of the materials I 
think it is very valuable to have the materials measured 
or tested in the manner prescribed, to see what pro- 
portion there is of all the different sizes and what 
proportion of voids each size leaves. But I do not 
think it is desirable to use materials of uniform sizes. 
I think the different proportions should be mixed for 
this reason, namely, that a uniform material, that is 
to say, a material in which all the particles are 
about the same size, will leave an amount of voids 
ranging from 30 to 50 per cent., or 45 per cent, 
(sometimes it comes up to near 50 per cent.), so that 
you cannot secure having the voids in that broken 
stone filled unless you have at least half its amount of 
sand. And you cannot secure the voids in that sand 
being filled by cement unless you have cement to at 
least half the amount of the sand, that is, if the broken 
stone and the sand are respectively of uniform size. 
But if the sand consists of particles of a good many 
different sizes, then the smaller particles will fill up 
some of the voids between the larger ones, and it will 
not require so much cement to fill up the ultimate ones 
—in fact, it will be found that in material where the 
particles consist of a lot of different sizes mixed, the 
total amount of voids will be a good deal less than if 
all the sizes are the same. In specifying mixtures for 
concrete that fact should be taken into account, and 
in order to know how to deal with your materials it 
is very valuable to know of what different sizes they 
are composed, and in what proportions those sizes are 
present, which, I think, is provided for. 

In the second Report, the time after the conclusion 
of the work before a test can be safely applied is 
very wisely specified. I have heard of tests being 
applied a very short time after the work was set, 
which was very risky, as such a proceeding is liable 
to break down a structure whose strength would 
ultimately have become all that was needed. Ninety 
days is, I think, a wise provision. 

Mr. WILLIAM G. KIRKALDY, Assoc. M. Inst. C.E., 
M.C.I. :■ — I did not come prepared to speak on this 
Report ; I was more interested to hear any points in 



TWENTY-SIXTH MEETING, April 25, 1912 243 

discussion that were raised, but I might be allowed 
to refer to Mr. Yeatman's point, which I thought the 
Report covered. Our view was it coincided exactly 
with Mr. Yeatman's comments, that the sand should 
contain as many different sizes as possible, so as to have 
as few voids as possible. The proposal for taking 
the voids separately was really to find out whether 
there was a preponderance of large grade in the sand 
or a preponderance of fine stuff ; the idea was that 
we should not have uniform sand, but to attack the 
question by finding out what the proportions were, 
to give a chance then to add any more of a certain 
size to make up any deficiency. If the sand ran too 
fine, with no coarse grade, there would be a chance 
to correct that. Certainly it is very desirable to 
get the size as varied as possible from the coarse 
down to the fine. That makes a denser concrete, and, 
of course, better work and a much higher physical 
strength too. The crushing strength is in very direct 
relation to the density of concrete ; when there are 
fewer voids you make it better. And, of course, it is 
economy in the cement as well, as it is wasteful to 
use cement for filling cavities, as used to be done in 
the old days before men studied concrete questions 
as they have done recently. 

I think, personally, with regard to the question of 
testing cubes it is rather desirable to have your data 
in, because some men may argue that ninety days 
seems a long time. But I think in this Report we 
may as well put forward what we think the best 
practice, and then any particular man, if he is tied 
for time, must use his own judgment. Personally, 
I think if you put the test on a structure too soon you 
may be doing harm. If the supervision has been 
close throughout on the job, that really ought to keep 
you right without the test load. But if you wish 
a test load, by all means make it on as late a date 
as you can ; do not put it on the work when it is 

green," or you may be seriously distressing it. 

I can assure the meeting that very great considera- 
tion was given to the Report by the members of the 
Committee, so as to try and cover all the ground. 
Of course, we aim high. Some men may think the 
tests are more complete than are necessary, but they 



244 THE CONCRETE INSTITUTE 

can always be cut down. The tendency in practice 
is to have fewer tests, but we have started out to give 
a programme of what we think would be advisable. 

Mr. D. B. BUTLER, Assoc. M.Inst.C.E., F.C.S., 
M.C.I. : — I am somewhat in the position of Mr. 
Kirkaldy, since I am a member of the Tests Standing 
Committee, and therefore I am criticising what is 
partly my own work. At the same time I may say 
this, that the Report in print does not appear quite 
the same as it did in draft, which is frequently the 
case. 

Referring to page 260, where the comparative tests 
are given between British standard sand and fine stone 
crushings, British standard sand, as we all know, is 
sand between oVth and ^th in. diameter — that is to 
say, it would pass a oVth in. sieve, but would be 
retained on a ^th in. sieve, whereas the fine sand 
from crushing all passed a -/oth in. sieve, and there- 
fore it is very much finer than the standard sand, and 
consequently it could not be expected to give such 
good results. Since the Report suggests that all sand 
which passes a -Lth in. sieve be rejected, I think it 
would have been more interesting if, with these com- 
parative tests between the fine sand and the standard 
sand, all sand passing a -Vth in. sieve had been 
eliminated from the fine sand. 

Referring next to page 268, paragraph (g), the 
Report says there : — 

In all cases specimen pieces shall be made 

in metal moulds, and the concrete worked in by 

punning and tamping and afterwards gently 

rammed." 

I am a little doubtful what the exact definition of 

" punning " and " tamping " is. I always thought 

both were a kind of ramming, and if so the Report 

recommends that " the concrete shall be worked in 

by ramming and ramming and afterwards gently 

rammed." (Laughter. 1 

Mr. Kirkaldy made one point as to the tests of 
concrete and suggested them being fewer. I think 
there is a good deal in that point, because I am afraid, 
if all these tests which are mentioned were carried 
out, with every load or delivery of aggregate, it would 
be extremely necessary to put in force paragraph 23 



TWENTY-SIXTH MEETING, April 25, 1912 245 

of the Report, by which the cost of testing should be 
provided for in the contract. 

Perhaps, gentlemen, I am more or less speaking 
against myself, since my own business, as most of 
those present are aware, is that of testing. At the 
same time, I do not think one benefits in the long 
run by making the tests cost too much. 

What struck me more particularly is what is stated 
on page 268 in the bottom paragraph, where it suggests 
that the voids should be ascertained of (1) the whole 
and (2) of each separate grading. Surely the latter 
is carrying it too far. Again, in the next paragraph 
( c ) The proportion of each grading to the whole, 
(e) The specific gravity of the coarse material and 
sand, (b) The exact dimensions of specimen cubes, 
(c) The weight per cubic foot of all specimens imme- 
diately before testing. Now, much of this seems to 
me to be needless expense, and I personally should 
not like to recommend a client to undertake all that. 
The same remarks apply, more or less, to the dates at 
which the cubes should be tested. I see the minimum 
tests suggested are from seven to twelve months. Well 
now, surely if one is to wait twelve months before one 
gets a final test the work has all been done, good or 
bad, and it cannot be altered. (Hear, hear.) It 
seems to me that anything beyond a twenty -eight 
days' test for control purposes is unnecessary. It may 
be useful for research and for reference afterwards, 
but for control purposes surely anything after twenty- 
eight days is not of much use. The same remark 
applies to the medium tests, which are carried up to 
two years, and the maximum tests, which extend to 
five years. Anything from two or three months up 
to five or six years is surely of value only for research 
purposes and cannot control the quality of the concrete. 

Mr. A. O. TRECHMANN, F.C.S., M.C.I. :— I did 
not expect to be called upon to speak this evening. I 
am not a member of the Committee and have not seen 
the Report before entering the room. It is, however, 
extremely interesting. 

It seems to me an excellent thing that the testing of 
concrete should be put upon a proper basis. The 
testing of cement in the past has been, in my opinion, 
not altogether satisfactory. 



246 THE CONCRETE INSTITUTE 

I might say that personally I do not see the object of 
testing cement in a neat state. I take it that cement 
is purchased as a cementitious material, and it is its 
cementitious value that you want to arrive at, and you 
do not arrive at that by testing a cement neat. I might 
express my meaning in this way : if one wished to 
test the value of a glue, one would never dream of 
making a test block of it and applying the tensile 
strain test, you would want to test the amount of 
adhesion acquired by the glue. I think the Germans 
are quite right to have eliminated the neat test entirely. 

I am a believer in the crushing test, and think it 
ought to be applied systematically. I have made a 
good many crushing tests for the purpose of com- 
parison with the tensile test, and the results are very 
interesting. 

Mr. R. N. SINCLAIR, M.C.I.:— Mr. Chairman, I 
find in the first page of the Report that pit gravel is 
included in the coarse material. I would like to ask 
if the Committee considered the advisability or other- 
wise of thoroughly examining this pit gravel, and, if 
necessary, washing it before it is used. One knows 
the loam and clayey matters that naturally accompany 
pit gravel, and I think in the majority of cases it is 
not good enough to simply take the gravel as it rises 
and use it for concrete. It is recognised that dredged 
ballast contains the minimum amount of foreign matter 
and often can be used right away, but this, of course, 
is not always available. 

Coming to the question of sand, on page 260, 
clause number 8, I am inclined to think that so 
far as sea sand is concerned, confining oneself to a 
screen having apertures of -Vth of an inch square it 
would be found that practically little would be retained. 

As to the question of grading the coarse material. 
Referring to a remark made by the first gentleman who 
spoke this evening, the provision in the report of 
meshes, the first mesh being £ of an inch by | of an 
inch, the retaining one J by g- of an inch, this seems 
quite satisfactory, and I cannot see that anything better 
could be provided. 

Coming to page 267, I should like to ask if the 
Committee have made up their minds that sea water 



TWENTY-SIXTH MEETING, April 25, 1912 247 

is not the water to use, and that fresh water is 
essential ? 

The Committee apparently do not recommend that 
one should specify the proportions of water to be used 
in cubes which are made for testing purposes. It 
seems to me that using a standard sand and a standard 
cement it is quite practicable, however, to do so. 

Coming to page 268, clause 2ig, this is a question 
which has already been touched upon. I had myself put 
a cross against that when I saw the paper. Personally, I 
do not quite understand it. One realises in practice that 
a lot depends upon how much " punning," " tamping," 
and " gently ramming " is given ; six men making 
six cubes may give six different results possibly out 
of the same gauging. I know it is a very difficult 
thing to say how much they shall do in the way of 
punning, etc., but I am afraid that a number of blocks 
made by one man who is not continually at it and 
knows exactly what to do will give varying results. 
I take it the harder it is "punned " and " tamped " and 
" rammed " the better the results. 

There is another question, the last I would like to 
take up your time with, and that is this : Have the 
Committee considered the question as to how long a 
time should elapse after the concrete is deposited in 
the moulds or on the shuttering before that shuttering 
is removed ? Of course, it is an important thing for 
a contractor in making up a tender, if he has a large 
area of floor and girders and beams to do ; it is one 
of the first things he looks at, and naturally he wants 
to find out how much of the shuttering he can re -use to 
finish the job, or how long must elapse after the 
concrete is deposited before he can take the forms 
down. It is a question we are face to face with in 
actual practice, and I think it is one well worth the 
Committee's consideration. 

Mr. PERCIVAL M. FRASER, A.R.I.BA, M.C.I. : 
— As a member of this Committee I would just like 
to try and answer one or two of the queries whidh 
have been put forward. The last speaker has rather 
mistaken the function of this Committee. It has not, 
in any sense, been the drawing up of a specification 
of workmanship and materials ; it is purely on ques- 
tions of testing. An engineer has certain materials, 



248 THE CONCRETE INSTITUTE 

made and unmade, and he has to put them to test, and 
this Report lays down the general rules that govern 
his testing of those materials. 

The last speaker mentioned the period for striking 
centering. That is not in any way a matter for this 
Committee to report on. I would like to draw his 
attention to the first words of the Report. This is 
an Interim Report, and a good many of the points 
which he has raised will no doubt be dealt with next 
session in a further Report. 

He spoke, quite rightly, I think, as to testing for 
cleanliness. I think that is an omission from this 
Report. It is a very vital thing to get your sand and 
aggregate quite clean, but it is, at the same time, 
more or less a matter-of-fact thing which everybody, 
I think, would do. Of course, it is elementary, but 
there is no reason why it should not have some place, 
so great is its importance. I think that also applies 
to other questions of a like nature — -namely, the sharp- 
ness of the sand. But, as I said before, we do not 
lay down here a general specification of materials. 

It is often said that fine stuff in sand is no detriment 
to the sand, but I think the Committee are wise in 
fixing the minimum size of -Vth in. by ^th in. In 
strict theory, a little below that size might be effica- 
cious ; but the danger is that you may get a great 
deal below that size, which is distinctly detrimental. 

With regard to determining the amount of water, 
the point is not to be laid down in hard-and-fast and 
dogmatic rules. Of course, the amount of water should 
be determined, but it should be determined by actual 
practice on one's work. One should decide, at the 
first go-off, what amount of water should be used and 
see it is carried out. There is only one way of 
determining that, and that is by an actual mixing. 

With regard to the amount of water to be used, 
that, again, is not a function of this Committee to 
decide. It was very exhaustively dealt with by a 
Special Committee of this Institute. 

On page 268, section 21, sub-section (e) it says : — 

" All laboratory -made test cubes shall be made, 
as far as possible, on practical lines . . ." 

But there is a value in a purely laboratory test. It 
shows the acme of strength which can be obtained 



TWENTY-SIXTH MEETING, April 25, 1912 249 

by those materials if they are really mixed on scientific 
lines. I do not care for laboratory -made tests unless 
they are frankly made for that purpose. 

With regard to paragraph (g), Mr. Butler says 
it reads, in effect, " ramming and ramming and after- 
wards gently rammed." (Laughter.) There was a 
fairly long discussion on that, and I think the 
Report would be benefited if a definition of those words 
were inserted — that is, the Committee's reading of 
those words. In my mind, there is a very great 
difference between " punning " and " tamping " and 
" ramming." " Punning " might be described as 
" poking," " tamping " as " slapping," and " ram- 
ming " as " punching " (laughter) ; " punning " is 
purely a " poking " action, " tamping " is a gentle 
patting to round off into position and level up, and 
" ramming " is to force the mass to consolidate purely 
and simply. 

The seven days' test is not usual for concrete. Most 
seem to think that fourteen days is the first valuable 
period at which you can test, or even twenty-eight, 
but I think a seven days' test is absolutely essential. 
Reinforced concrete work in these days is generally 
rushed through pretty quickly ; we want to find out 
equally quickly what kind of material we are dealing 
with. 

A gentleman suggested the elimination of neat tests 
of cement, but I think that is going a trifle far. We 
know that the tensile strength of neat cement is, say, 
750 lbs. to the inch ; we have learned by indirect 
experiment the practical result we are likely to get 
from a neat cement which stands such a tensile 
strength, and until we have educated ourselves up a 
little more I do not quite think we ought to drop it. 

Mr. Butler rather criticised his own Report, and if 
we amend this Report to Mr. Butler's ideas we shall 
have a Minority Report, which is very valuable in 
a way. He thinks that testing each grade of aggregate 
and sand for voids is going too far, but in view of 
the purely nominal cost of measuring for voids — the 
total cost on each sample being about 2s. 6d. for all 
grades — it would not seem to be doing too much to 
test for voids from a bulk which will represent any- 
thing up to 10,000 yards or more. 



250 THE CONCRETE INSTITUTE 

Mr. BUTLER : — Might I point out the variations 
in the delivery each time ? 

Mr. FRASER : — No, there should be no such varia- 
tion. If you are not satisfied you are getting a 
uniform ballast you had far better condemn it. 

Mr. J. B. TRAVERS SOLLY, Assoc. M. Inst. C.E., 
M.C.I. :— With reference to the size of sand, I under- 
stand that this Report is not supposed to deal with 
materials used in concrete, but only with the question of 
testing the material. Eut still the Committee have made 
the remark that it is important that all sand that is not 
retained on an aperture of 3 1 (7 th in. X ^Vth in. should 
be rejected. Well, concrete work is not all done in 
England, and in some places it is very difficult to get 
the carefully graded sand that is advised by the Com- 
mittee. And with reference to that, I would like to 
mention that in some cases it might be better to use 
a sand that has a comparatively large proportion of 
fine dust than to use a drift sand with rounded edges. 
I had the opportunity of testing mortar under those 
conditions. The mortar was i cement, 2 sand. I had 
drift sand which was very rounded, and I had crushed 
sand which had a very large amount of flour. The 
briquettes were tested at seven and fourteen days, 
and I think I had three briquettes for each test. With 
ordinary mixing, starting with drift sand (that is, the 
rounded edged sand ) and cement, and from that to the 
crushed sand containing flour, with ordinary mixing, 
at seven days I got an increase of 29 per cent, in 
strength — tensile, of course. With the same crushed 
sand, using more water and mixing it very thoroughly, 
I got an increase of 69 per cent. At fourteen days 
I got similar increases of 20 per cent, and 34 per cent., 
and I attributed it entirely to the fact that the crushed 
sand was sharp -edged sand, whereas the drift sand had 
no sharp edges. I think in every case the quality of 
the sand can be very easily judged under a magnifying- 
glass, and that ought to be taken into consideration 
in connection with the question of passing a sand that 
has fine grading. With reference to the testing of 
briquettes, or rather the condition in which the 
briquettes should be kept, I see here it is specified on 
page 270 that all specimens shall be kept in air after 
mixing and slightly damp for the first seven days. 



TWENTY-SIXTH MEETING, April 25, 1912 251 

I may be behind in date ; I did not know that that 
was the usual system. Up to the last time I was doing 
any testing we covered the briquettes with a damp 
cloth for twenty-four hours, then took them out of 
the moulds and placed them in water, and they were 
kept in water for the six days, making seven days 
in all, and then tested. I am not singular in that 
practice, because I had lately an opportunity of hearing 
a paper read dealing with an engineering work upon 
which very large quantities of cement had been used. 
The author particularly drew attention to the fact that 
the briquettes were kept in water for seven days, and 
his experience was that the tensile strength of those 
briquettes varied very much according to the length 
of time that they had been left out of the water before 
testing. As he said, while in the laboratory every- 
thing could be done more correctly, according to rule, 
on the works sometimes it is not quite so easy, and 
on taking briquettes which had been kept out of water 
half an hour up to twelve hours before they were 
tested, he found a very great drop in their strength. 
In one case, at any rate, there was a loss of 30.0 lbs. 
to the square inch in the tensile strength of the 
briquette that had been left out of water for twelve 
hours, and he suggested that in all testing the rule 
should be laid down, to obtain uniformity, that the 
briquettes should be tested within half an hour of the 
time they are taken out of water. 

Mr. ARTHUR WILLIAM BUNGARD, Licentiate 
R.I.B.A., M.C.I. : — I do not intend to discuss the 
Report, but may I ask one or two questions ? In the 
first place I find in the Report that the tensile strength 
of the steel required is given, but I do not find any 
strength mentioned as to crushing, or the tensile 
strength of the concrete. I do not know whether 
the Committee have left that out accidentally, or did 
not intend giving it. If they give it for the steel, why 
not for the concrete ? 

In the second place, with regard to the cubes. The 
actual work will be done by labourers, and it seems 
to me that the six cubes should be made on the works, 
and the tests should be made on those cubes and not 
on laboratory -made cubes at all. You would first find 
out what the test is required in the laboratory, and 



252 THE CONCRETE INSTITUTE 

then see that the other cubes are made on the job 
by the men who will lay the stuff, and only have those 
particular cubes tested. I would ask, "Is it not 
possible for the result of the test on the laboratory - 
made blocks to be far higher than on those which are 
made by the navvy?" 

With regard to paragraph 23 on page 270, " The 
Committee is of opinion that for the purpose 
of providing for the cost of testing a provisional sum 
should be included in all contracts where such testing 
will be required, this being the most satisfactory and 
fairest way to all parties concerned." 

I think that the builder would allow for that. If 
he were told that he had to provide for tests, would 
he not allow for that in his tender ? 

Mr. KIRKALDY : — The speaker before last was 
doubtless thinking of the ordinary tensile briquettes of 
cement. In the last page of the Report, the Committee 
are referring entirely to concrete samples being kept in 
air. The damping of concrete cubes is to prevent 
them drying out prematurely. They should be kept 
damped for the first few days, but it does not refer 
to the briquette testing for the quality of the cement ; 
such briquettes are universally kept in water until time 
of testing. 

Mr. BUTLER :— It does not differentiate. 

Mr. KIRKALDY :— I think I am quite right in 
saying that it was concrete we were dealing with in 
that part of the Report. It is all under clause 22. 

I am sure the discussion to-night will be very useful 
to the Committee that are considering these points. 

I may say points have been very fully discussed in 
Committee, but it is always interesting to get outside 
views. The men outside are apt to raise points that 
we may have forgotten. I look forward with interest to 
have these thrashed out again ; no doubt the Report 
will be made clearer from that. 

Mr. YE ATM AX : — Might I be allowed to mention 
one point I omitted before, that is, whether clause 1 8 
and 1 8a on page 268, providing for a large percentage 
of elongation or contraction of area at fracture, do not 
practically bar out the use of a higher tensile steel which 
would stand more than 60,000 lbs. per square inch, 



TWENTY-SIXTH MEETING, April 25, 1912 253 

but would not elongate so much as the figures given. 
I understand that tests on twisted square bars, even 
though they are made of steel of about that quality, 
show that the twisted bars have a considerably higher 
ultimate strength, and a very much higher yield point. 
They will stand about 60,000 lbs. before showing 
much elongation, but I do not think they will extend 
25 per cent, before fracture ; but they make a very 
good material for reinforcement, and can be safely 
subjected, I think, to a higher strain than the ordinary 
medium steel bars. 

MR. GEORGE S. ROBERTS, M.C.I. .—There are 

two points I should like to raise on the Interim Report. 

We are anxious that we should know as much 
about the materials we have to use in concrete con- 
struction, and it is only right that we should do so, 
but reading over this Report I think, as another speaker 
has already mentioned, that unless we are careful 
we shall hinder and not promote the interests of the 
subject. 

I take it we are all here to push forward this method 
of construction, and I think it is one of the best and 
cheapest forms of construction, but if we are going 
to frighten people into thinking that unless everything 
is perfect they will have no faith in this method, and 
it will also make the cost nearly prohibitive. 

Speaking as a contractor, the amount of money 
that one would have to lay out in plant, to enable 
the suggested tests to be carried out in actual work, 
would, I feel -sure, make it impossible to get the 
work out at a reasonable figure, and if it is to be more 
costly than another form of construction, we are losing 
one of the inducements we can hold out to clients. 

By all means give us as much knowledge as ( you 
possibly can, so that we can carry out the work 
efficiently and well, and know that when it is finished 
it will stand, but do not harass us with unnecessary 
testing, which does no good, and only increases the 
cost. The whole crux of the question is to employ 
men who thoroughly understand this work, and with 
reasonable supervision there is not likely to be much 
worry . 

The suggestion of a provisional amount for testing 
is a good thing, but will clients agree to it ? Will 



254 THE CONCRETE INSTITUTE 

not they say the contractors must see to this 
themselves ? 

Mr. TRECHMANN :— The question of the quality 
and the size of the sand used for concrete has been 
raised. The cleanness of sand is, of course, absolutely 
essential, and I think some test ought to be indicated 
by which the suitability of the sand, its freedom from 
loam, etc., should be determined ; and, secondly, as 
to the size of the sand. It appears to me that in pre- 
paring a Report of this kind, one is rather apt to 
assume that every kind of good material is available, 
wherever work to be carried out may be situated. But, 
supposing that sea sand is the only sand obtainable, it 
is not improbable, as one of the speakers suggested, 
that all or nearly all of it would pass through the 
xoth by sVth inch sieve. Now, if such a sand must 
be used, would it not be as well to specify the increased 
quantity of cement to be used with it, to make up 
for the increased number of particles and surface 
area as compared to a standard sand ? 

THE CHAIRMAN (Professor Adams') :— In order 
that the work may be reliable a,nd accord with the 
calculations, it is necessary to make careful and uni- 
form tests of the materials as actually employed, but it 
appears to me that some of the tests proposed are 
more adapted for purposes of research than for the 
stability of the work. Remarks have been made about 
pit gravel ; pit gravel was once either river gravel 
or sea gravel, and the difference from exposed gravel 
in nearly all cases is that there is a certain amount of 
iron oxide attached to it, and often loam, and when 
pit gravel is used, it is specially necessary to see that 
it is clean. 

On the second page, the little table at the bottom 
shows in a very striking way, I think, the necessity 
for excluding all dust from the work. The dust, in 
a sense, goes to fill up all the interstices, but in order 
that it may usefully fill them up, every particle of dust 
must be encased in fine cement, therefore a greater 
proportion of cement is necessitated. 

At the International Congress of Architects some 
few years ago, I called attention to the desirability of 
grading the larger aggregate, reducing the maximum 



TWENTY-SIXTH MEETING, April 25, 1912 255 

size down to 1 in. or f in., and giving all sizes in 
between down to J in. At that time it was customary 
to only specify the larger size, whatever that might 
be, sometimes as large as i| in., and firms even adver- 
tised their broken brick of uniform size as if that was 
a great recommendation for it. Now, we find all 
specifications practically state that the material is to 
be graded. 

With regard to the question of grading the sand, 
I do not think that is so important as grading the 
larger material, but it enables us to use some larger 
particles of sand than has formerly been the custom. 
On the diagram, one matter struck me as rather 
curious, " Sea-sand (on shore for twenty -six years)." 
I should like to know from what evidence that age is 
assigned. (Laughter.) 

Mr. ALBAN SCOTT :— Before I reply, Mr. Chair- 
man, it is quite a simple matter, although it has caused 
laughter. This sea-sand was carted twenty-six years 
previously by known facts right inland from the sea, 
and it has been on a heap for that number of years, 
and we originally used it in a large water-tank, and 
these are the results of experiments made to ascertain 
the voids from that sea-sand actually used. 

THE CHAIRMAN :— That puts it on quite a dif- 
ferent basis. I thought the sand had been on the 
sea -shore for twenty-six years. It says, " (on shore 
for twenty -six years)," and that seemed very curious. 
It had left the sea for twenty -six years ; that is the 
explanation. 

MR. ALBAN SCOTT :— That is right. 

THE CHAIRMAN :— I suppose all the salt was 
washed out of it by that time ? 

With regard to testing the steel, no rate of applica- 
tion is mentioned. It is as necessary 1 , I think, in testing 
steel as in testing cement, to have a uniform rate of 
application. 

With regard to the contraction of area, or the 
elongation, the tendency appears to be at the present 
time 1to prefer the test for contraction to that for 
elongation, possibly, to some extent, because there 
used to be at least three standards of length : 6^ in. — 
that is, 100 i6ths of an inch — 8 in., and 10 in., and 

R 



256 THE CONCRETE INSTITUTE 

then later some shorter lengths still were put in, so 
that the percentage of elongation would vary with 
each of those lengths, although it was the same 
identical material. 

The " working-in " and " punning " and " tamp- 
ing " are varieties of very useful processes, but I think 
possibly the Committee might be able to improve 
upon the wording they have adopted. The Committee 
recommend that a provisional sum should be included 
in all contracts for the cost of testing. That is a 
counsel of perfection. They give no idea of what 
that cost will be. If we could have verbally in the 
discussion some idea of the cost that these recom- 
mended tests would run to it might be useful. On a 
large contract there is no difficulty, as a rule, in 
getting the client to agree to the tests, but on a small 
contract it is really out of the question. 

With regard to testing the finished structures, very 
little has been said about that in the discussion. I 
think it is open to grave risks. Suppose the structure 
is in such a condition as to need the test, then the 
greatest risk is caused, because you are straining parts 
beyond their elastic limits, we will say, or creating 
incipient cracks which do not fail at the time. Per- 
haps the point is clearer in the case of machinery. It 
came to me very forcibly some years ago, when the 
Home Office were formulating their Regulations for 
docks and riverside warehouses as to the care of chains 
and machinery for lifting. They argued that the 
machinery should be tested with the full load 
periodically, and that that would be satisfactory. I 
advised them that, in my opinion, that would be most 
unsatisfactory, because it would lead to this : A 
machine might be tested — we will say it is doing 
nothing but being tested — time after time with the full 
load until ultimately it would give way with the full 
load. But the time before that, when it was tested, it 
took the full load and did not fail, therefore it is 
no safeguard, and particularly in the case of crane 
chains. I have had a very large quantity of these 
through my hands, and the responsibility of those 
chains and the men working under them, and I was, 
from experience, always against the repeated testing of 
a chain by mechanical tests. My practice was to have 



TWENTY-SIXTH MEETING, April 25, 1912 257 

the chains periodically taken off, fired, annealed, and 
examined link by link, but not put under a mechanical 
test, and I believe that the examination in that way 
was a much greater safeguard than a mechanical test. 
And so with regard to testing the finished building. 
It is very much better to see that you have proper 
supervision, proper designs, and proper checking of 
those designs before the work goes in hand, than to 
rely upon any tests that you may make upon the 
finished work afterwards. 

Mr. A. ALBAN H. SCOTT :— Mr. Chairman and 
Gentlemen, I shall be glad if you will kindly take my 
reply as personal remarks and not in any way as the 
official reply of the Committee. During the course of 
the discussion it seemed very strange that no one raised 
objection or discussed the tests on steelwork. From 
this I think we are safe in concluding that you are 
all of opinion that tests on steelwork are highly desir- 
able. We have had a good deal of criticism on the 
tests for the concrete. As there is. a much larger 
human element employed in the making of finished 
concrete than there is in the making of steel there is 
more chance of defects in the finished concrete, and 
I think the Committee would be still working in the 
proper direction if the tests on concrete as suggested 
by them remain unmodified. 

The proposed tests on steelwork in the Report are 
now accepted practically by every rolling-mill, always 
provided you give them good notice so that they can 
get proper billets from which to roll the metal to 
withstand the tests. I feel quite sure that very shortly 
every engineer and contractor will accept without 
hesitation the tests which we have suggested in this 
Report. 

On March 8th I gave a paper on this subject at the 
Society of Architects, and one point I tried to make 
particularly was that at the present moment various 
official rules are taking 1,800 lbs. as the ultimate 
strength of concrete, and are taking 600 lbs. per 
square inch as a working load. Working to these 
loads, it is absolutely imperative that you should have 
the very best concrete, and if you are dealing in 
concrete at all, then you must have the very best or 
leave it alone altogether. 



258 THE CONCRETE INSTITUTE 

Dealing with the criticism on the question of grading 
aggregate and sand, we have had no difficulty at all 
in getting aggregate and sand graded to whatever 
proportion we wish, and it is quite a commercial pro- 
duct. This graded material must be obtained from 
crushers. The method of sifting Thames ballast and 
rejecting everything over the size required is a thing 
of the past. I feel quite sure that if concrete is not 
tested, and we only rely upon haphazard methods, we 
can very shortly anticipate disastrous failures in rein- 
forced concrete work. We have had a few already, 
from what causes I will not enter into now ; but we 
shall be certainly increasing our percentage of failures 
unless the actual concrete used in structures is more 
carefully watched and brought to a higher standard, 
unless the various rules, official and otherwise, are 
altered so that the present limiting value of 1,800 lbs. 
is reduced to at least 1,500 lbs. Concrete test cubes, 
properly taken and properly tested from the actual job, 
will not give such results as to justify 600 lbs. as the 
actual working stress. You will see from the Report 
of the Society of Architects' meeting my feelings on 
the matter as regards the testing of structures after 
completion. I think such tests are not only undesir- 
able, but are inviting trouble. The testing suggested 
in the Report we have been discussing this evening 
seems to have frightened some of the members present,, 
but this Report is put in the form of a model, and must 
of necessity aim at the ideal. When you come to 
consider the actual cost involved, it is not so serious 
as you would anticipate. On reinforced concrete work 
costing about £10,000 the tests suggested can be 
comfortably carried out, if properly arranged, for about 
£150, and I do not consider that such a small per- 
centage on the cost of the work for testing is ex- 
travagant ; but whether it is a high or low sum, as 
long as we use reinforced concrete work it is essential 
that it should be tested, and £150 is just as necessary 
and desirable as it is to have the centering for 
constructing the work. 

Dealing generally with the question of concrete, the 
greatest trouble seems, to be the extent of competi- 
tion in prices, and it is not always desirable in rein- 
forced concrete work to accept the lowest tender. 



TWENTY-SIXTH MEETING, April 25, 1912 259 

The question of safety of the building is much more 
important than the question of saving a few hundred 
pounds. 

The cleanliness of gravel is extremely important, 
and some most extraordinary results have been obtained 
recently on tested samples. Up to April 8th we only 
had one or two samples tested, and about 7 per cent, 
of loam was the average result. Since that date we 
have conducted a series of tests, and we find that loam 
in gravel varies from 5 per cent, to 29 per cent, of 
its bulk in weight. Strange as it may sound, the 
material containing 29 per cent, of loamy matter 
looked perfectly clean. 

Mr. Butler raised a serious question with regard 
to the table on page 260. That records the result of 
practical tests made very carefully to see the extreme 
effect of dust, and it did show that it had a very bad 
effect upon the finished material. Since that date we 
have had four more tests carried out on other dust, 
which have more than confirmed the conclusions arrived 
at in the case referred to. 

One gentleman raised a question as to a certain 
shaped bar. I do not wish to continue to bring in 
any patent bar ; it is undesirable at this meeting, and I 
do not feel quite free to criticise it, but, at the same 
time, in any metal that is twisted, when it is twisted 
cold, the actual centre of the bar remains the same 
dead length as before twisting, whereas, taking a square 
bar, the corners considerably increase in length, and 
it is certainly a question yet to be determined what 
effect there is on metal so distorted. 

Mr. BUTLER :— It gets very brittle. 

Mr. ALBAN SCOTT :— Mr. Fraser dealt with some 
of Mr. Butler's criticism on item 22, but I would 
mention with regard to the exact dimensions of the 
concrete cube and the exact weight of same and minor 
points, so far as the cost is concerned, they are most 
important for the purpose of the test. 

One gentleman discussed the question of the removal 
of centering. This does not come under this Com- 
mittee's Report, but I would like to call special atten- 
tion to the fact that the seven and fourteen days' tests 
on concrete cubes will materially help in determining 
at what age the work is strong enough to sustain loads 



260 THE CONCRETE INSTITUTE 

without such centering. The question of the pro- 
portion of water has also been raised, and if you 
refer to the Society of Architects' Journal for April, 
on pages 222-27 y° u w iU find particulars of a series 
of tests, one series of which is most particularly in- 
teresting. This was undertaken by Mr. Kirkaldy on 
sixty-four cubes, and it conclusively proved that the 
drier the concrete is and the more ramming or tamping 
it receives the better the results. This is confirmed 
by every other test which we have carried out, and, 
further, it must be borne in mind that the exact pro- 
portion of water in concrete must vary considerably, 
according to the nature of the concrete and sand, and 
also on the condition of the weather. 

In conclusion, I would like to express my personal 
view that in the present stage of reinforced concrete 
there are many irresponsible contractors and designers 
taking the work in hand ; and in issuing such a Report 
as this Committee take upon themselves to do, it is 
better to err on the side of carefulness rather than 
to say, " Go ahead ; put in the concrete the same as 
you put the concrete around drains." 

THE CHAIRMAN (Professor ADAMS) :— Gentle- 
men, I am sure it will be in accordance with your 
wishes that I should express the thanks of the meeting 
to the Tests Standing Committee for this Report, and 
particularly to Mr. Kirkaldy, the Chairman, and Mr. 
Alban Scott, the Honorary Secretary, because we all 
know that upon those two officials the work of the 
Committee chiefly falls. Mr. Alban Scott has also 
given us the extra advantage of reading the second 
Report to us to-night and replying upon the discussion. 
(Applause.) 

The meeting then terminated. 

The Tests Standing Committee, having subsequently 
reconsidered their reports in view of the foregoing 
discussion, make the following addenda : — 

(1) The Committee cannot see their way to alter 
or amend Clause 9, and suggest that if 
sand smaller than will pass a -gVth m « by 
^oth in. sieve be used that more cement 
should be employed. 



TWENTY-SIXTH MEETING, April 25, 1912 261 

(2) The Committee is of the opinion that com- 
pression tests on cubes are desirable ; if, 
however, it be considered that the cost 
involved in the least of their recommenda- 
tions would be excessive for any particular 
job, then their recommendations of a series 
of tests should be carried out as far as 
possible. 



THIRD ANNUAL GENERAL MEETING 
Thursday, May 9, 191 2 

THE THIRD ANNUAL GENERAL MEETING of 
the CONCRETE INSTITUTE was held at Denison 
House, 296, Vauxhall Bridge Road, London, SAY., on 
Thursday, May 9, 191 2, at 4.30 p.m., 

Sir HENRY TANNER, C.B.. I.S.O., F.R.I.B.A.. 
President, in the Chair. 

The following were elected members of the 
Institute : — 

Christopher William Ballexdex, Johannes- 
burg. 

Spexcer Edwards, Barnstaple. 

Cecil Thomas Lewis, Ilford, Essex. 

Harold Lixgard, Madras, India. 

Percy J. Pike, Assoc. R.San. Inst., M.Inst. San. E., 
Stud. Inst. Mun.E., Southend. 

Arthur Regixald Sage, Assistant Principal of 
L.C.C. School of Building, Brixton, S.W. 

Iax M. Sutherland, Victoria, Australia. 

ALLAN Graham. A.R.I.B.A., London. 

THE SECRETARY (Mr. H. KEMPTON DYSON) 

then read the Report of the Council as follows : — 

REPORT OF COUNCIL FOR 1911-12 SESSION. 

The Concrete Institute had on April 30, 191 2, 881 
Members, 24 Students, and 11 Special Subscribers. 

The increase in membership from the foundation of 
the Institute is recorded in six monthly periods in the 
accompanying chart. 



REPORT OF COUNCIL FOR 1911-12 SESSION 263 

The Finances of the Institute are, as shown by the 
accompanying Balance Sheet, in a satisfactory con- 
dition. 

The General Meetings and Visits are duly recorded 
from time to time in the TRANSACTIONS, and there- 
fore are not included here. The thanks of the Institute 
are due to the authors of the papers and to those who 
acted as hosts on the occasions of the visits referred to . 

The Council has in the past year been concerned 
with numerous technical and administrative matters. 

One of the principal items occupying the attention 
of the Council and a Joint Committee of the Science 
and Reinforced Practice Standing Committees has been 
the consideration of the proposed Regulations made 
under the provisions of Section 23 of the London 
County Council (General Powers) Act, 1909, with 
respect to the construction of buildings wholly or partly 
of reinforced concrete. A draft of suggested Regula- 
tions was submitted by the Superintending Architect of 
the London County Council to the Institute for its 
consideration, and the action taken was recorded in the 
Annual Report for the 1910-11 Session. The 1909 
Act referred to provides that the Concrete Institute, 
together with the Institution of Civil Engineers, the 
Royal Institute of British Architects, and the Surveyors' 
Institution, shall have notice of the Council's intention 
to apply to the Local Government Board for the 
allowance of any regulations as to the use of reinforced 
concrete in the county of London, and such notice was 
duly given at the beginning of December, 191 1. The 
Institute's suggestions as to the amendment of these 
regulations have been sent to the Secretary of the 
Local Government Board and to the Superintending 
Architect of the London County Council, and in due 
course the Council of the Concrete Institute will be 
able to inform the members as to the outcome of such 
action. 

In October, 191 1, a proposal for widening the scope 
of the Institute was considered by the Council and 
referred to a Committee whose report was approved 
on March 14, 191 2 ; an abstract of the report is 
appended. The members of the Committee are : Mr. 
E. F. Etchells (Chairman), Professor Henry Adams, 
Mr. Alexander Drew, Mr. Charles F. Marsh, Mr. 



264 



THE CONCRETE INSTITUTE 




(IPX) sjsqiuajij jo jsqiunx 



REPORT OF COUNCIL FOR 1911-12 SESSION 265 

W. G. Perkins, Mr. Edwin O. Sachs, Mr. H. D. 
Searles-Wood, Mr. L. Serraillier, Sir Henry Tanner, 
and Mr. E. P. Wells. 

A seal, medal die, and certificate of membership have 
been designed and engraved for the Institute by Mr. 
Cecil Thomas, and the certificates of membership have 
been issued to all the members who have paid their 
subscriptions for the current year. 

The question of awarding a bronze medal for the 
best paper read in the previous session was decided by 
ballot among the members of Council, and as a result 
the medal has been awarded to Professor Beresford 
Pite, F.R.I.B.A., for his paper entitled " The /Esthetic 
Treatment of Concrete." 

Sir Henry Tanner has been appointed delegate of 
the Concrete Institute at the Congress of the Royal 
Sanitary Institute to be held in June next. 

The International Association of Road Congresses 
have asked the Institute to appoint delegates to the 
Third International Road Congress to be held in 
London in June, 191 3, and delegates will be appointed 
after the Annual General Meeting has taken place. 

The following Members of the Council resigned in 
the past year : Mr. William Dunn, Captain J. Gibson 
Fleming, Sir Douglas Fox, Mr. W. T. Hatch, Mr. 
W. H. Johnson, Mr. F. May, Sir William Preece, and 
Mr. Alexander Ross. The Council co-opted the follow- 
ing to fill some of the foregoing vacancies : Mr. 
H. Percy Boulnois, Mr. Alexander Drew, Mr. A. Alban 
H. Scott, and Mr. L. Serraillier. 

In consequence of the resignation of Sir Douglas 
Fox and Sir William Preece as Vice-Presidents of the 
Institute and of the retirement of Sir William Mather, 
Mr. William Dunn, Mr. C. S. Meik, and Mr. F. E. 
Wentworth-Sheilds were appointed to the vacancies 
in November. Mr. William Dunn and Mr. Alexander 
Ross resigned as Vice-Presidents in March and Mr. 
H. Percy Boulnois and Mr. E. P. W T ells were elected in 
their stead. 

Sir Henry Tanner's term of office as President ex- 
piring in May, Mr. E. P. Wells was appointed 
President for the ensuing two years. The Council 
is pleased to record that Sir Henry Tanner will 
continue as a Member of Council in the capacity of 



266 



THE CONCRETE INSTITUTE 



o 
o 
u 

o 

< 

K 
P 

5 
w 

0- 

w 

Q 
Z 
< rt 

Cd > 
O 

z 



0) 



o 

Q 






■ - tr, m o o - 
t~ -r o ■" O « 
00 o o M oc w 



I- - o. « 



S, r? 3 



c <£ « * 2 Z 

-> ."""- = 
-an 



" " - [-■ M 

« K £ -> ' - _ 

— . = sj: ^ E s ,„ 

u --/-•--- = ■- £ 

■j 'j •- - — - c •- •* u 

£ = "" -E - z i « 5 2 

OO i. i p < 35 « J 

>, . ...... 2 



o o 
o c^ 



- 


B 


~ 


| 




'rr 


~L 




a 




2 



— 






^ 




- 




u 


























7 








■j. 




*«1 


K 


, 


— 


n 

3 




"£ 


C 


= 


f 






c 

OB 






C 

c 


X. 


X 


- 
> 


£ 















- 


' 


" 


H 







- 

z 

D 
O 
O 

u 

< 

o 
J 

Q 
Z 

< 



— 









•3 « ""• 


t^ 


Qj 


^ \r. it. 


c 


Cu 


S?3- "■ 


* 
S3 



?. £ o 



o ^ = 



3 ** "5 

B5 



REPORT OF COUNCIL FOR 1911-12 SESSION 267 









-x 


O 


u~. 


f 


M 


fO 


O 





X 


O 


O 


s 







■0 


r'. 


> 








u 

c 


5 

a 


'5s 




- M 


<1- 


g 


E 


S 










O. 







O X 


N 


u 




"m 







m 


01 

> 


u 


B 


< 


O CO 




re 




5. 


< 


n 




£ 


X 


X 


J 























V 


u. 








'j 


£ 










c 










J3 






w 








■= 


T3 
C 


M 






T3 


cq 


« 


J 






C 

re 


j; 


B 



> 



.a • 


re < 


!j 




S ii 


'3 tn 


Q g 




u re 
-0 -a 


i- 


g6 




J. c 2 


Q "g 


ry) - ^ 




w m 2 


-*p re 


~ <u 




K - ~ 


CT" 4J 


^ .* 


-1 


3 "> .£ 


sc 


c = 






- 


1 re re 


re 


1 " * 




J. 03 03 


£ 



5 2 § 



o g = 



rt 
U 



^ 

Q 



O <M 










(3 






T3 
















a> 03 

















z 2 
















're x: .3 










2 






















.c 
















-c £ 










hi 






















S'lS 










"&> 


X 




re - C 














_ 3 






? 




a 




/- 


6 


« if* 


» 




^ 

S 




5 


a 


s 


£ ^ -3 


B 

3 


z 


a; 


. 




y. 


•SI 


ibers 
Decen 
corre 





z 

< 




t/3 

-J 
J 




z 

H 




c -a 


•0 


>■ 








S 




" -5; c 

CO W 

J! T3 = 
^ 5) J 


c 

z 



as 
z 
w 

3 






SB 




sli! 


n 


„■ 
















2" 1 












"u "S -2 















u IS 


















>^ 


* 3 













0) O 



268 THE CONCRETE INSTITUTE 

a Past President and continue to give the Institute 
that help and guidance which has been so valuable in 
the past. 

It has been decided that Chairmen of the various 
Committees shall be subject to annual election or re- 
election, and that the lists of members of the Standing 
Committees shall be revised after each annual election 
of Members of Council. It has been decided also that 
Chairmen of the Committees shall be ex-officio 
Members of the Finance and General Purposes Com- 
mittee. 

The First Annual Dinner of the Institute was well 
attended and passed off successfully. The attendances 
at the two days' Summer Meeting were not satisfactory, 
and it has not been thought advisable to hold similar 
meetings this year. 

During the present Session a larger number of 
Meetings will have been held than in any previous 
Session, and next Session it is intended to resume the 
course of Educational Lectures to Students which were 
begun last Session. The work of the Institute is in- 
creasing, and it is hoped to extend the number of 
Meetings next year and that the subjects to be dealt 
with will be of more general interest by reason of the 
extension of the scope to cover structural engineering 
generally. 

A Library is in process of formation at the Institute 
and a number of donations have been received, but the 
Council would welcome the presentation of books, 
papers, and other publications on the subject of 
structural engineering generally, the funds at present 
precluding any large purchase of such works. A 
catalogue of works in the Library will eventually be 
published and members will be enabled to borrow 
books. 

The Transactions will in future be issued quarterly 
and articles or notes from members will be welcomed 
for insertion therein. In order to meet the extra cost 
it is proposed to invite advertisements, and the assist- 
ance of members in this direction will be valuable. 

The Finance and General Purposes Committee has 
held regular meetings preliminary to each Council 
Meeting, and the general results of their deliberations 
are recorded in the foregoing particulars of the work 



REPORT OF COUNCIL FOR 1911-12 SESSION 269 

of the Council during the year. Mr. H. D. Searles- 
Wood and Mr. G. C. Workman were appointed 
Members of the Finance and General Purposes Com- 
mittee in June, 191 1, in lieu of Mr. W. T. Hatch and 
Mr. L. Serraillier. 

As regards the work of the Science Standing Com- 
mittee, the Institution of Municipal and County 
Engineers requested the opinion of the Concrete 
Institute upon a Standard Specification for Concrete 
Flags which they proposed issuing and the Committee 
made a number of suggestions which the Institution 
has intimated will be considered in any revision they 
may make in the future of their Specification. The 
Standard Notation for calculations for reinforced 
concrete which was drafted by the Science Committee 
and approved by the Council continues to meet with 
favour and has been adopted by the Joint Committee 
on Reinforced Concrete appointed by the Royal 
Institute of British Architects in their Second Report 
and by the London County Council in their proposed 
regulations covering the erection of buildings of rein- 
forced concrete in London. Authors of textbooks 
have also employed it and the American Joint Com- 
mittee on Concrete and Reinforced Concrete have in- 
formed the Science Committee that they have the 
Notation under consideration with a view to its 
adoption in any further Report they may make. 
Professor Henry Adams and Air. E. F. Etchells were 
appointed Chairman and Vice -Chairman respectively 
of the Science Standing Committee in June. Mr. 
F. E. Wentworth-Sheilds having resigned as Hon. 
Secretary of the Committee, Mr. H. K. G. Bamber 
was appointed in his stead. The Committee have the 
following matters under consideration : — 

(1 ) Reinforced concrete piles. 

(2) A chemical test for steel used in reinforced 

concrete. 

(3) The standardisation of attachments or joints 

in reinforced concrete. 

(4) The adhesion of or friction between concrete 

and steel. 

(5) A standard notation for calculations in structural 

engineering generally. 



270 THE CONCRETE INSTITUTE 

(6) A standard specification for reinforced concrete 

work. 

(7) The effect of sewage on concrete. 

(8) The effect of oils and fats on concrete. 

The Science Committee appointed the following as 
representatives of the Institute upon the Joint Com- 
mittee on Loads on Highway Bridges which is con- 
ducted by the Concrete Institute : Professor Henry 
Adams, Mr. William Dunn, Mr. Charles F. Marsh, and 
Mr. C. S. Meik. The other members are as follows : — 

John A. Brodie, M.Eng., Wh.Sc, \ Representing the 

M.Inst.C.E. I Institution of 

A. E. Collins, M.Inst.C.E. [Municipal and 

J. W. Cockrill, M.Inst.C.E. j County Engineers. 

A. E. Prescott, M.R.San. I. \ Representing the 

Henry C. Adams, Assoc. M.Inst.C.E., ' Institution of 

A.M.I.Mech.E., A.M.I.E.E. Municipal 

H. C. H. Shenton, M.R.San. I. j Engineers. 

The Joint Committee has had one meeting and has 
issued inquiry forms to municipal authorities and others 
soliciting information respecting the vehicles that have 
to be sustained in various parts of the country as a 
preliminary to drafting recommendations. 

The Tests Standing Committee have issued reports 
on " The Testing of Concrete, Reinforced Concrete, 
and Materials Employed Therein " and " The Testing 
of Reinforced Concrete Structures on Completion." 
These have been discussed at Ordinary General 
Meetings of the Institute. The Committee have the 
following matters under consideration : — 

(1) The effect upon steel of the presence of sulphur 

in aggregates. 

(2) The grading of aggregates. 

(3) The expansion and deterioration of concrete due 

to changes of atmospheric temperature. 

(4) The effect of the use of sodium silicate on the 

surface of concrete as affecting reinforcing 
metal . 

(5) The erratic results obtained by the Vicat needle 

in ascertaining the initial set of cement. 



REPORT OF COUNCIL FOR 1911-12 SESSION 271 

The Reinforced Concrete Practice Standing Com- 
mittee have drafted reports on the subject of " The 
Standardisation of Drawings for Reinforced Concrete 
Work " and " The Consistency of Concrete/' which 
have been discussed at Ordinary General Meetings of 
the Institute. The Committee have also had under 
consideration a reference of the Council for a report 
as to clauses in contracts for reinforced concrete work, 
but the Committee recommended the Council that they 
were of the opinion that the formulation of clauses in 
contracts was a legal matter, and the Committee did 
not feel they were capable of formulating such clauses. 
The Committee are still investigating : — 

(1) Methods of treating the surface of concrete. 

(2) Cracks due to the expansion and contraction 

of reinforced concrete. 



APPENDIX. 

ABSTRACT OF REPORT OF THE COMMITTEE 
APPOINTED TO CONSIDER THE WIDENED 
SCOPE OF THE CONCRETE INSTITUTE. 

On October 26, 191 1, a proposal for extending the 
scope of the Institute was considered by the Council. 

After considerable discussion it was unanimously 
resolved that : — 

" The Council do approve in principle the proposal 
for enlarging the scope of the Institute." 

It was also unanimously resolved that a Committee 
be appointed : — 

(a) To consider how the above Resolution could 

best be carried out. 

(b) To take energetic steps to develop the Structural 

Engineering side of the widened scope. 

The Committee of ten members of the Council was 
elected, and Mr. E. Fiander Etchells was appointed 
Chairman . 

At a series of meetings it was resolved that : — 

Scope. 

(a) Clause 3 (1) of the present rules does not 
limit the scope of the Institute to concrete and rein- 

s 



272 THE CONCRETE INSTITUTE 

forced concrete, but that the clause enables the Institute 
to deal with iron (including steel), bricks, gravel, sand, 
cements, and other structural materials and their 
application. 

Definitions. 

(b) For the purposes of the Institute, Structural 
Engineering be defined as that branch of Engineering 
which deals with the scientific design, the construc- 
tion, and the erection of structures of all kinds in any 
material. 

(c) Structures may be defined as those constructions 
which are subject principally to the laws of Statics, 
as opposed to those constructions which are subject 
principally to the laws of Dynamics and Kinematics, 
such as engines and machines. 

Title. 

(d) After very long discussion, the Committee came 
to the unanimous decision that the term " The Concrete 
Institute " should remain in the title, and that it should 
have the first place in the title and that a sub -title 
should be added, so that the full title and sub -title 
should be — 

THE CONCRETE INSTITUTE, 

AN INSTITUTION FOR STRUCTURAL ENGINEERS, 
ARCHITECTS, Etc., 

and that such description should be added to all 
documents wherever practicable. 

Lectures and Examinations. 

(e) An annual course of technical lectures on some 
branch of Structural Engineering be instituted. 

(/) Examinations in Structural Engineering be held 
by the Institute once a year, to test the scientific or 
technical attainments of applicants for Studentship . 

Subscriptions. 

(g) An entrance fee of one guinea be required 
when the membership reaches one thousand. 



REPORT OF COUNCIL FOR 1911-12 SESSION 273 

Transactions. 

(h) TRANSACTIONS should be issued quarterly. 

(/) Members should be requested to return the 
reports of discussions at meetings not later than seven 
days after receipt and that the following circular letter 
be sent to speakers : — 

" In order to facilitate publication of the 
Transactions, early return of the enclosed re- 
port of your contribution to the discussion of 
the above-mentioned paper is requested. The 
Council have directed that reports which are not 
returned to the Institute within one week shall 
be published in the form shown." 

(/') Members be hereby invited to submit a note as 
to suggested papers covering all branches of Structural 
Engineering. 

(k) New books received should be reviewed in the 
Transactions. 

(/) A referendum be employed to ascertain the 
wishes of the members as to : — 

1 . The most convenient meeting -place. 

2. The most suitable hour of meeting. 

(m) The time is not yet ripe for any change of 
rules, but that the suggestions in this Report should 
be worked upon for twelve months as a trial. 

The Committee desire to state that valuable infor- 
mation has been collected in connection with the 
revision of Rules, and this information will be filed 
for future reference, and is to some extent embodied 
in the Minutes of the Committee's proceedings. 

DISCUSSION. 

THE CHAIRMAN (Sir Henry Tanner) :— In 
moving the adoption of this Report, there does not 
seem to be very much that I can add to the full state- 
ment which has been made, but there are two or 
three points which I should like to emphasise. So 
far as our membership goes, we are on the increase 
slightly. We have not gone back, which is a very 
great point. We have lost a great many members, 
but, on the other hand, on the balance there has been 
a slight advantage. I suppose, having regard to the 



274 THE CONCRETE INSTITUTE 

very large membership that we obtained at first, we 
ought to be satisfied with even making some slight 
progress. 

Ihen, as to our finances, they are none too good, but 
still they are on the right side. I think we have 
been, perhaps, at an abnormal expense this last year 
in providing office furniture and other things, but 
now we are established there ought not to be that 
expense. We still have got some money on deposit, 
which is a very good feature. 

The London County Council Regulations have 
occupied most of the members of the Council and the 
Sub -Committees. I think, however, that we have done 
very good service in what we have sent to the Local 
Government Board. 

Then, as to the Scope, you will think probably that 
the Report of that Committee does not go very far, 
still a quiet commencement has been made, and we 
hope we are going in the right direction, and that 
we shall make the Institute of more extended interest 
to our members, and, therefore, we shall increase our 
numbers, at least that is our hope. 

As to the Library, we have got very few books, and 
we should like as many members as possible to make 
us gifts of books. I daresay there are many members 
who would be very anxious to do that if they only 
knew what was wanted. 

The Science Standing Committee, and the Tests 
Standing Committee, and the Reinforced Concrete 
Practice Standing Committee have all done useful 
work, and you will see, stated very clearly in the 
Report, what they have been engaged upon during 
last session, and I consider that we ought to be very 
thankful to those Committees for giving so much time 
and attention to the business. 

We have dropped the educational lectures this 
session, but it is one of the proposals of the Committee 
on the Scope of the Institute that these should be 
resumed next session. 

With these few observations, gentlemen, I propose 
that the Report be accepted by the meeting. 

Mr. EDWIN O. SACHS, V.P.C.I., F .R.S.Ed. :— I 
merely wish formally to second the Report. It con- 
tains much that will be of interest to the majority of 



REPORT OF COUNCIL FOR 1911-12 SESSION 275 

members who are far away, and which I trust they 
will read carefully. There is much that might well be 
made the subject of debate, but on an occasion like 
this we all wish to have an unanimous adoption of the 
Report, and thus a debate would be out of place. It 
is a great pleasure to me to be able to second it. 

There is one paragraph in the Report, however, 
which I should like to particularly point to, and that is 
the second paragraph on page 6. I wish to call 
attention to the fact that we are losing our President, 
Sir Henry Tanner, and we will all agree that that is, 
I am sure, a very great loss. Sir Henry Tanner has 
steered this Institute through two years of very critical 
times. I think, to put it quite plainly, that Sir Henry 
Tanner held the Institute together, because the Institute 
when he started his presidency was only about three 
years old. It was a very young child, but was some- 
what of a handful. It had all the ailments, as I think 
I once said before, that children are apt to get. But 
Sir Henry Tanner acted as nurse and doctor in one, 
and it grew to be robust if not larger in size under 
his treatment. Latterly the Institute has also made a 
spurt at growing, and thus when Sir Henry Tanner 
leaves the Chair it will fall to our friend, Mr. Wells, 
to see that this is no mere spurt but a regular growth. 

I think it should be pointed out very plainly to 
what a very great extent we are indebted to Sir Henry 
Tanner for having guided us, and I take this oppor- 
tunity of emphasising that point, as I understand that 
any remarks on the Report appear in the Transac- 
tions, and our many members who are away in the 
Colonies will thus be informed of our views of the great 
services rendered by the retiring President. I have 
very much pleasure in seconding the adoption of the 
Report. (Applause.) 

Mr. LUCIEN SERRAILLIER, M.C.I. :— May I sug- 
gest, sir, that it might be desirable to delete the words 
" after considerable discussion " at the bottom of 
page 271, and state " that it was unanimously resolved 
that the Council do approve in principle the proposal 
for enlarging the scope of the Institute." I think there 
was no doubt on that Committee that it would be 
desirable to enlarge the scope, so that to say " after 
considerable discussion " would imply that there was a 



2/6 THE CONCRETE INSTITUTE 

difference of opinion on that point. I think the dis- 
cussion took place on the way in which the scope 
should be widened. Then, on page 158, do you think 
it is desirable to ask the assistance of members in 
canvassing for advertisements for the TRANSACTIONS ? 
Would it not be better to leave that out ? 

THE CHAIRMAN (Sir HENRY Tanner) :— The 
mere fact it has been put in answers its purpose. 

Does anybody second these two propositions ? 

After a pause : — 

THE CHAIRMAN (Sir Henry Tanner) :— You 
have no seconder. 

Mr. H. PERCY BOULNOIS, M.Inst.C.E., 
V.P.C.I. : — Speaking to the Report, Mr. Chairman, as 
a new member of this Institute and my first 
appearance at any of your meetings, I should like to 
support the adoption of this Report and to congratu- 
late the Council upon the work which they have done. 
There are one or two questions I should like to ask, 
and, first, with regard to the lectures that are proposed. 
I take it that the lectures are paid for — that is to say, 
you have paid lecturers ; they do not give th^ir 
services gratuitously, and that the students attending 
pay a fee ? I do not see anywhere in the Report that 
that is stated, and young men might come and ask 
me, and I should not be able to tell them anything 
about it. I do not know whether that could in some 
way be added, or in your reply you could tell me what 
the fees would be ? 

Then, with regard to the TRANSACTIONS being issued 
quarterly ; this will be very expensive, because I notice 
now that your Transactions and other printing has 
cost £228, and unless we get the advertisements, which 
my friend seems to object to, or rather to members 
canvassing for advertisements, we shall make a very 
heavy loss. As the American says — 

" Early to bed and early to rise, 
Is not the least bit of use unless you advertise." 

(Laughter.) It is a well-known fact with journals 
and all papers they do not pay unless they have 
advertisements, and they are very costly to produce 



REPORT OF COUNCIL FOR 1911-12 SESSION 277 

unless you can introduce advertisements. Personally, 
I do not see any harm in members, not exactly can- 
vassing for advertisements, but trying to obtain them 
for the Journal. 

As I say, the work that this Council has been doing 
is extraordinary in the way of investigation, and the 
list of things that you have either considered or are 
about to consider almost appals me, because I under- 
stand I have been elected on the Council, and if I am 
to take part in this gigantic work I really tremble 
to think what the. consequence may be. On page 159 
you have a list of seven matters which you are going 
to consider, from reinforced concrete piles down to 
the effect of oils and fats on concrete. On page 160 
you have got the effect upon steel of the presence of 
sulphur in aggregates, and four others, winding up 
with the erratic results obtained by the Vicat needle 
in ascertaining the initial set of cement, and, lower 
down, methods of treating the surface of concrete 
and cracks due to expansion and contraction of rein- 
forced concrete. All that is a terrific programme, and 
I only hope that we shall be able to get through 
one-tenth of it. 

I was going to suggest another investigation, and 
that is, when we hear of failures in concrete that a 
committee should thoroughly investigate the reason 
of those failures. Fortunately we have not heard of 
so many lately, but many of them are mostly exag- 
gerated. I do think that something of the kind should 
be done, that where we do hear of any failure in rein- 
forced concrete we should thoroughly investigate it, 
and see if it is due to the reinforcement of the concrete 
or to some other cause. I have great pleasure in 
supporting the adoption of the Report. 

AIR. T. C. DAWSON, Assoc. M. Inst. C.E. :— I have 
only one suggestion, in also supporting the Report, 
and' that is, in the TRANSACTIONS the advertisements, 
if obtained, be not embodied in the pages of the 
ordinary matter, but kept at either end. 

Mr. F. E. WENTWORTH-SHEILDS, M.Inst. C.E ., 
Y.P.C.I. : — I should just like to say, sir, that I am 
very pleased to see that the Committee who had in 
charge the suggestions for widening the scope of the 
Institution have suggested as the sub-title " An 



278 THE CONCRETE INSTITUTE 

Institution for Structural Engineers, Architects, etc." 
I am very delighted to see that "etc.'" — (laughter) — 
because I think there was a little tendency at one time 
for our Improvement Committee to rather rule out 
anybody except engineers and architects ; and I think 
it is the strength of this Institute, sir, that we have 
been able to combine so admirably the brains and the 
work and the good fellowship of so many different 
men representing the building trade and profession 
in all sorts of different ways. We have engineers, 
we have architects, we have specialists, we have 
chemists, we have contractors, we have every sort of 
person who is interested in structural work. This 
feature of the Institute is in some ways unique, and 
has been of immense help to us — it has enabled us to 
get the various subjects which we have investigated 
looked at from all points of view. I hope it will 
continue to the end of the chapter. 

About advertisements, I sympathise with Mr. 
Serraillier's idea. It is not very nice to have to 
advertise, but, on the other hand, we must face the 
fact that we have got a great deal of expense, and 
that we have not got enough money coming in for that 
expense. Well, surely it is better to put advertise- 
ments in our Journal rather than raise the subscription 
and so make it more difficult for those who would like 
to join the Institute and get its advantages. Probably 
this thought will reconcile us even to the terrible idea 
of having this or that brand of cement or of rein- 
forcement writ large at the end of our Journal. 

THE CHAIRMAN (Sir Henry Tanner) :— There 
are not many points which I have to answer. The 
principal ones are the observations of Mr. Sachs, in 
which he used such flattering words in regard to 
myself. I am not aware that I have done so very 
much, but of course I have had the interest of the 
Institute at heart ; I have done what I could for it, 
but every one of us has done the same and we all 
work together. However, I am very much obliged 
to Mr. Sachs. 

Then Mr. Serraillier made some observations. We 
do want the advertisements for the income which we 
hope that they will bring in, and we shall put them at 
both ends of the book. The Institute of British Archi- 



REPORT OF COUNCIL FOR 1911-12 SESSION 279 

tects and the Architectural Association both accept 
advertisements, so that I cannot see any harm in our 
doing it. The Civil Engineers do not, but that Institu- 
tion is much better off, which makes all the difference. 

In regard to the question about the lectures, we 
have only had one course of lectures, and we neither 
paid the lecturer nor did the students pay a fee. ; I 
cannot see why they should not, and I cannot see why 
the lecturer should not have something for his trouble 
and out-of-pocket expenses. Anybody who wants lec- 
tures by way of instruction should pay something for 
them. That is a matter which the Council will have 
to consider before they issue the particulars. 

Then as to the printing of the quarterly issue, we 
have had many complaints as to the irregularity of 
the publishing of the Transactions. They got 
rather out of date and people forgot all about them, 
and they were not of so much service, so we decided 
that they should be issued quarterly. We have cut 
down the size, and also altered the type, producing 
them on a cheaper scale. They are quite adequate 
for the purpose, and we also propose still further to 
reduce the cost by sub -editing some part of what 
is submitted for appearance there in the future, and 
we propose to leave out some of the particulars as to 
Committee meetings, etc., not usually published. 

The subject referred to by Mr. Boulnois should be 
examined into, but it is not so easy to do so, as failures 
are kept secret as a rule. (Hear, hear.) 

As to what Mr. Wentworth-Sheilds said, of course, 
the " etc." was meant to cover anybody not exactly 
belonging to the two professions, and the wider we 
can spread ourselves so much the better it will be for 
us and the more support we shall get generally. 

With those explanations, which I hope are satis- 
factory as far as they go, I will now put the proposi- 
tion that the Report be received and adopted. 

On a show of hands : — 

THE CHAIRMAN (Sir Henry Tanner) .-—That 
is carried. 

I will now read you the Report of the scrutineers on 
the Annual Election of Members of Council. 



280 



THE CONCRETE INSTITUTE 
[Copy.] 



May 1, 1 9 1 2 . 
Dear Sir,— 

We, the Scrutineers to the Council Election of 
the Concrete Institute, have found as follows : — 



Section I. 



Votes. 



Shore, T. B 








.. 181 


Serraillier, Lucien ... ... ... 177 


Munro, John... ... ... ... 176 


Section II . 


Searles-Wood, H. D. ... ... 160 


Bamber, H. K. G. 




.. 156 


Vawdrey, R. W. 








.. 136 


Boulnois, H. Percy 
Drew, Alexander 








132 
132 


Scott, A. Alban H. 








132 


Garbutt, Matt 








.. 123 


Harvey, R. Xapier 
Davis, A. C 








.. 105 

92 


Fraser, Percival M. 








73 


Hills, Osborn C. 








72 


Tingle, H. J. 
Watson, T. Aubrey 
Wager, Jasper 








50 

35 
32 


le hundred and nil 


1€ 


ty-five 


voting 


-papers 



were 
received. 

There were four spoiled papers. 

The votes of two members had to be ignored owing 
to their subscriptions being in arrear for 191 1. 

Three papers were rejected owing to the envelopes 
not being signed. 

Yours truly, 

(Signed) P. W. Leslie. 

A. W. Buxgard. 
The President, Concrete Institute. 



THE CHAIRMAN (Sir Henry Tanner) :— The 
first twelve-named are elected. We issued with the 
voting-papers a paper asking the opinions of members 



REPORT OF COUNCIL FOR 1911-12 SESSION 281 

as to the time of the meeting and whether they con- 
sidered the Hall satisfactory, and the result was 59 
voted in favour and 1 1 against the present Meeting 
Hall ; in regard to the hour of the meeting, $y voted 
for 7.30 p.m. and 30 for 8 p.m. So as regards the 
Hall, it seems quite satisfactory, but on the other point 
opinion is nearly equally divided, and the Council will 
have to take the matter into consideration. 

Mr. JASPER WAGER, A.R.I.B.A., M.C.I. :— I am 
asked to move the appointment of Messrs. Monkhouse, 
Stoneham & Co. as Auditors of the Accounts for this 
year at a fee of five guineas. 

Mr. T. C. Dawson, M.C.I. :— I second that pro- 
posal, and I do so with great pleasure. 

THE CHAIRMAN (Sir Henry Tanner) then put 
the resolution to the meeting and it was unanimously 
adopted. 

THE CHAIRMAN (Sir Henry Tanner) :— The 
next business we have is to present our medal to 
Professor Beresford Pite — (cheers) — which the Council 
has awarded to him for his paper on " The .Esthetic 
Treatment of Concrete," and in presenting it I should 
like to say that it was a most interesting contribution 
to the literature of the subject treated ; and it gave 
rise to some discussion, although this was limited in 
extent. The architects did not turn up, as we had 
hoped, to take a considerable part in it. We expected 
that they would, as we had sent a very wide invitation 
to them ; but I think there were only two or three 
who came to hear and to discuss this paper. 

I am glad that the Professor did not altogether 
object to what had been done and advocate something 
entirely new, because I think we should have got into 
Aery much trouble, and the results would have been 
much like they are in some foreign places, where the 
architecture in reinforced concrete is not very satis- 
factory, to Englishmen at all events. But he did 
not do that ; he said we ought to start from the 
existing styles of architecture, and that seems really 
to be the mo'st satisfactory way of meeting this diffi- 
culty, because it is a real difficulty. Nobody has 
developed anything yet which, when new, is satis- 
factory. However, there is no doubt that something 



282 THE CONCRETE INSTITUTE 

will develop shortly, and the Professor has given us 
a start in that direction. Perhaps the Royal Institute 
might develop a discussion itself, and so make some 
greater effort than has been done hitherto. It rather 
sits upon this sort of thing. I do not think I need 
waste your time in saying anything more, but I would 
ask the Professor's acceptance of this small memento 
of our regard for him and his lecture. (Applause. > 

THE CHAIRMAN (Sir Henry Tanner) then 
handed Professor Beresford Pite the Bronze Medal of 
the Society for the best paper read in the 1910-11 
session. 

Professor BERESFORD PITE, F.R.I.B.A., 
M.C.I. : — I beg most sincerely and heartily to say how 
much I appreciate the honour that the Council of the 
Institute has conferred upon me in bestowing this 
medal for the paper. It is due, of course, to the 
interest of the subject, which dealt with an aspect of 
work in concrete that has not yet captured the imagina- 
tion of members of this Institute as I hope it will in 
the future. One cannot but be sure that if the apparent 
fog that hangs over progress in the architectural 
aspects of concrete construction is dispelled by a little 
clear light there ought to be a considerable acquisi- 
tion of width and breadth to the operations of this 
Institute. So long as this subject remains unexplored 
and unexperimented upon, so long this Institute will 
be looked upon as merely a body concerned with 
certain aspects of building, and with those only ; and 
concrete construction, especially in its more prominent 
methods now, will be relegated to the larger, coarser, 
and greater class of building, when it might, if their 
interest and enthusiasm and hope and light are 
awakened, be used for more monumental, decorative, 
and homely, and therefore much wider, purposes. 

It seems to me that since it is recognised that there 
is a field for experiment, for movement, and for in- 
tellectual thought, a field which connects a contract in 
concrete building with an ordinary and regular course 
of architectural study of aesthetic construction, then 
there should come the widened scope which your 
Special Committee so hope for, and which they have in 
a way suggested, by adding the word " Architects " 
to the title of the Institute. That widened scope will 



REPORT OF COUNCIL FOR 1911-12 SESSION 283 

come with a very broad;, large, and I should like to 
say popular, appreciation of the artistic possibilities 
of concrete, because the popular aspect of this subject 
is, of course, one closely allied to the commercial one. 
The union of the commercial constructional aspect and 
the popular artistic aspect ought to make this Institute 
a very wide and a very important public body. 

I should only like, sir, to make one suggestion with 
regard to this, which I think is a practical suggestion, 
and not inappropriate, connected with the honour 
that you have courageously bestowed upon an un- 
worthy person to-day, the suggestion is that this 
subject should not be dropped, but the attention 
of architectural students and designers should be drawn 
to it. The Chairman has indicated that the Institute 
of British Architects do not pay much attention to 
it. He is perfectly right. I think if he had said 
bluntly that they are prejudiced with regard to the 
whole subject of concrete he would only have spoken 
what he feels, and what with some delicacy we know 
he hesitated to express. The best way to disperse 
that prejudice will be to show what great and good 
designs can be perhaps imagined, because every castle 
has to be built in the air before it can be built on the 
earth by young and enterprising designers, and the 
setting up by this Institute of an annual competition in 
designs would, I think, attract at all events a certain 
number of responses ; but I am sure it would attract 
a few intellectual and careful thinkers on the subject 
of aesthetics. Those students who have little else to 
think about in their youth but the charm of design, 
will turn with interest to such a competition, if the 
Medal which you have now created, and which is such 
an artistic object, is bestowed with such monetary 
attraction as either a special fund or some contri- 
bution from the Institute as it might be able to afford 
annually for a design would supply, the subject of 
a design being to deal with the simple architectural 
aspects, elevation, and details suitable for application 
to, or execution in, reinforced concrete, with, if neces- 
sary, any descriptive theory as to the method of design. 
I think, without expecting too much in the way of hard 
labour from the competitor, the Institute will be put 
into possession annually of a number of interesting 



284 THE CONCRETE INSTITUTE 

artistic essays, that is to say artistic inventions, or 
designs, and will attract to itself the attention of 
students as well as to its meetings, and having 
the designs, no doubt, sir, they will be as beneficial 
to the publication of your proceedings as the adver- 
tisements with illustrations at the end. (Applause and 
laughter.) 

Personally, I always look upon those advertisements 
with a great deal of interest when they deal with 
technical and practical subjects. The illustrations of 
designs in reinforced concrete would have a most im- 
portant influence upon the whole subject. Any one 
who takes up the Transactions will say that here 
is a live and popular aspect of the question, which this 
Institute is alive to, you will attract to yourselves those 
of the general public who are very widely interested 
in the outward aspects of the buildings, and of art 
critics and others who certainly should be made con- 
scious of the fact that a new and effective building 
material has come into practical use. The world will 
move, as it always has moved in these artistic matters, 
slowly, but with increasing interest, life, and 
enthusiasm. 

Again I venture to thank you very humbly and very 
earnestly and very cordially for the kindness of your 
presentation this afternoon. (Applause.) 

THE CHAIRMAN (Sir Henry Tanner i :— The 
next business, gentlemen, is for me to vacate this Chair 
and to put Mr. Wells into it. In Mr. Wells I am 
sure you will have a President quite suitable to the 
Institute, not an amateur — (hear, hear) — one who is 
thoroughly acquainted with the business or with the 
profession of a designer in reinforced concrete, not 
like myself, an amateur, and I am sure he will make 
you a most excellent President, and I feel great con- 
fidence that the Institute will certainly advance under 
his guidance. (Applause.) I therefore will make way 
for Mr. Wells and wish him the best possible luck 
during his two years of office. 

Mr. E. P. WELLS, J. P., accordingly took the 
Chair and said : Sir Henry Tanner and gentlemen, I 
have to thank Sir Henry especially for the very kind 
words that he has said, and for the manner in which 
vou have received the same. I do not intend now 



REPORT OF COUNCIL FOR 1911-12 SESSION 285 

making any remarks, but to say that during my term 
of office as President I trust that in all my dealings 
with every member I shall be thoroughly impartial, 
and I shall do the best thaft I can for the interests of 
the Institute. (Applause.) 

Mr. A. ALBAN H. SCOTT, M.S. A., M.C.I. :— I 
have the pleasure of proposing a very hearty vote of 
thanks to Sir Henry Tanner for taking the President's 
position for the last two years. I hesitated to accept 
chis duty this evening because I felt it should be in 
more capable hands ; fortunately, however, Mr. Sachs 
has already said practically everything which should be 
said on an occasion of this s,ort, and I can only heartily 
endorse his feelings. 

It will be most difficult to secure another President 
to take up such energetic work on behalf of this 
Institute as Sir Henry Tanner. He has given up an 
immense amount of time, and the courtesy which he has 
always shown to every one with whom he has come 
into contact will also never be exceeded, and further, 
Sir Henry has always been on the spot when he has 
been required, and if Mr. Wells is so fortunate as to 
be able to follow such a splendid precedent it will 
spell further progress for the Institute. I have the 
greatest pleasure in proposing a most hearty vote of 
thanks to Sir Henry Tanner. (Applause.) 

Mr. W. G. KIRKALDY, Assoc. M. Inst. C.E., 
M.C.I. : — I should like to be allowed to say, in 
seconding Mr. Scott's proposal, that I think the 
Institute and all the members are very much indebted 
to the labours of Sir Henry Tanner, who has thrown his 
whole heart into it during the last two years. As Mr. 
Sachs has said, he has steered us through rather critical 
times and worked exceedingly hard. There are not 
many institutions who are so fortunate as to have 
presidents who have given so much energy to their 
work. I am only too glad to know that we shall 
have "his hearty co-operation afterwards, although not 
in the Chair. 

Personally, I should like to record the great pleasure 
I have had in working with Sir Henry Tanner. I 
am sure every member on Committee who has come 
into contact with him has experienced his great 
courtesy, and also his business ability in pushing things 



286 THE CONCRETE INSTITUTE 

forward, in getting a lot of work through in a very- 
short time, and yet by his courtesy in hearing any 
remarks in discussion he has been able to draw out, 
I think, the points of all parties. It has been a great 
pleasure to me to come into contact with him, and I 
just make these remarks in seconding the proposal of 
thanks. (Applause.) 

THE CHAIRMAN (Mr. E. P. WELLS) :— I now 

put this to the meeting, that a most hearty vote of 
thanks be accorded to Sir Henry Tanner for occupying 
the Chair for the last two years as President, which 
has been so ably proposed by Mr. Scott and seconded 
by Mr. Kirkaldy. I will put that to the meeting, and 
I am sure every one will join in it with acclamation. 
(Applause. > 

The resolution was adopted by acclamation. 

Sir HENRY TANNER :— Gentlemen, I have had 
great pleasure in listening to what has been said, and 
I thank you extremely for the vote of thanks which you 
have given me for any services which I have rendered 
during the past two years. Mr. Sachs has already 
made observations to this effect, and I have answered 
them, and that takes rather the wind out of my sails 
at this time ; but I can only say that it has given me 
very great pleasure to attend these meetings and the 
meetings of the Council. I have made many friends 
there, and I hope to continue my attendance. I have 
continued as President of the Institute for as long as 
was beneficial to it, and there are many who are 
more gifted for such a position than myself. I think 
you have now a President better fitted for the purpose 
than I have been. We have, however, got the business 
through, and we have arrived at a point which is 
certainly not backward from what it was two years 
ago, and for that I have to thank the members of the 
Council, our Secretary, and all concerned. I thank you 
very much, gentlemen, for your vote of thanks. 
(Applause. ) 

The meeting then terminated. 

The accompanying photographs illustrate (exact 
size) the bronze medal presented to Professor Beresford 
Pite. The obverse is the same as the Seal of the 



REPORT OF COUNCIL FOR 1911-12 SESSION 287 

Concrete Institute. Mr. Cecil Thomas (of 1, Great 
Pulteney Street, Regent Street, London, W.), who 
designed and engraved the seal, medal dies, and certifi- 
cates of membership, has supplied the following 
explanation of the design of the medal : — 

" The motive of the obverse is : Great strength com- 
bined with beauty ; typified in the strong and firm 



19IO-I9II 

pass en-ted" to 

A.BERESFORDPJTE . 

\ for his f^AJ»a« _ ? r* 

"^ KHTr I TtfiO TH E *£ 

l\ JESTHe'TJC,^;''' 




'T TREATMENT £X. 
>.H COW CRETE '>"/; / 







THE MEDAL OF THE CONCRETE INSTITUTE. 



yet beautiful female figure, who holds an important 
implement used in concrete building. The Lions of 
Alfred Stevens ornamenting a simple throne and the 
ornamental border surrounding the whole indicate the 
artistic nature and strength of concrete construction. 

" Reverse : Laurel and Oak for success and 
strength." 



THE SECOND ANNUAL DINNER 

Thursday, May 9, 19 12 

THE SECOND ANNUAL DINNER of the CON- 
CRETE INSTITUTE was held on Thursday evening, 
.May 9, 191 2, in the Empire Hall, at the Trocadero 
Restaurant, Piccadilly Circus, London, W. 

Mr. E. P. WELLS, J. P., President of the Institute, 
was in the Chair, and there were also present : — 

As Visitors of the Institute. 

Mr. H. Percy Boulnois, M.Inst.C.E., V.P.C.I., Chair- 
man of the Council of the Royal Sanitary 
Institute. 

Mr. R. Elliott-Cooper, M.Inst.C.E., President-Elect 
of the Institution of Civil Engineers. 

Lieut. -Colonel G. E. Holman (of Holman & Good- 
shaw, architects > . 

Mr. John Murray, F.R.I.B.A., Crown Survevor. 

Mr. W. E. Riley, R.B.A., F.R.I.B.A., M.Inst.C.E., 
Superintending Architect of Metropolitan 
Euildings and Architect of the London County 
Council. 

Mr. E. A. Stickland, President of the Institution of 
Municipal Engineers, Borough Surveyor, 
Windsor. 

As Members. 

Mr. H. H. D. Anderson, Mr., Maurice Behar, C.E. 

Member of Council (Ecole des Ponts et Chau- 

Mr. H. K. G. Bamber, F.C.S., sees) 

Member of Council Mr. F. Bradford 



THE SECOND ANNUAL DINNER, May 9, 1912 289 



Mr. C. St. Leger Brockman 
Air. D. B. Butler, 

Assoc. M.Inst.C.E., F.C.S., 

Member of Council 
Mr. Walter Butler, M.Inst. 

C.E. 
Mr. F. Dare Clapham, 

F.R.I. B.A. 
Mr. T. M. Deacon, F.S.I. 
Mr. C. cle la Salle 
Mr. William Dunn, F.R.I. B. A., 

Past Vice-President 
Mr. E. Fiander Etchells, 

F. Phys. Soc, M.Math.A., 

A.M.I. Mech.E., Member of 

Council 
Mr. Albert A. Fillary, District 

Surveyor for Streatham 

West 
Mr. Percival M. Fraser, 

A.R.I. B.A. 
Mr. James Gardiner 
Mr. George H. Gascoigne 
Mr. George W. Gray, P. A.S.I. 
Mr. F. W. Hamilton, 

A.R.I.B.A., District Sur- 
veyor for Paddington 
Mr. Charles D. Hunter 
Mr. W. P. Inchley 
Mr. Charles J. Jackaman, 

M.Inst.C.E. 
Mr. William G. Kirkaldy, 

Assoc. M.Inst.C.E., Member 

of Council 
Mr. P. W. Leslie 
Mr. James A. Malcolm 
Mr. John Munro, Member of 

Council 
Mr. Stanley V. Nicholson 
Mr. W. G. Perkins, District 

Surveyor for Holborn, 

Member of Council 
Mr. James Petrie 
Air. Joseph Randall, 

Assoc. Inst. C.E. 



Mr. George S. Roberts 
Mr. Reginald Ryves, 

Assoc. M.Inst. C.E. 
Mr. Percv W. Sankey, 

Assoc. M.Inst. C.E. 
Mr. A. Alban H. Scott, M.S.A., 

Member of Council 
Mr. L. Serraillier, Member of 

Council 
Mr. C. W. Sharrock 
Mr. Herbert Shepherd, 

A. R.I. B.A. 
Mr. T. B. Shore, Member of 

Council 
Mr. Alfred Stevens 
Mr. J. Osborne Smith, 

F.R.I. B.A., F.R.San. I. 
Mr. Samuel F. Smith 
Mr. Samuel A. Stanger, F.S.I. 
Sir Henrv Tanner, C.B., 

I.S.O., F.R.I. B.A., F.S.I., 

etc., Principal Architect 

H.M. Oi'tice of Works, 

Past P resilient 
Mr. Henry Tanner, F.R.I.B.A., 

Member of Council 
Mr. John M. Theobald, F.S.I. 
Mr. Thomas P. Tinslay 
Mr. C. G. Napier Trollope, 

M.A., F.S.I. 
Mr. F. E. Wentworth-Sheilds 

M.Inst.C.E., Dock En- 
gineer L. & S. W. Rly., 

Vice-President. 
Mr. J. H. Wardley, 

Assoc. M.Inst.C.E. 
Air. G. C. Workman, M.S.E., 

Member of Council 
Mr. Anthonv White 
Mr. A. E. Williams, 

Assoc. AI. Inst. C.E. 
Mr. Jasper Wager, A.R.I. B.A. 
Mr. Wyndham K. Wise 
Mr. Percy L. Young, 

Assoc.M.I.AIech.E. 



290 



THE CONCRETE INSTITUTE 



As Friends of Members. 



Mr. W. H. Aston 

Captain A. Bovd-Carpenter, 
West Riding C.C., Ex- 
Mavor of Harrogate 

Mr. C. A. Breeze, B.Sc. 

Mr. R. P. Bronsson 

Mr. Arthur G. Cross, F.S.I., 
Hon. Secretary of Quantity 
Surveyors Association 

Mr. C. V. Chapman 

Prof. J. D. Cormack, B.Sc, 
Assoc. M.Inst.C.E., Pro- 
fessor of Mechanical En- 
gineering at University 
College, London 

Mr. H. Horace Cunis 

Mr. H. H. Dalrymple-Hay, 
M.Inst.C.E., Chief Con- 
struction Engineer, Under- 
ground Railways of London 

Mr. W. J. Downer, I.S.O., 
J. P., Assistant Secretary of 
H.M. Office of Works 

Mr. E. S. Flinn 

Sir W. Alfred Gelder, M.P., 
F.R.I. B.A. 



Mr. H. P. Heap 

Mr. Charles Heathcote, 
F.R.I. B.A. 

Mr. C. R. S. Kirkpatrick. 
M.Inst.C.E., Chief Assis- 
tant Engineer, Port of 
London 

Mr. George A. Lansdown, 
F.RI.B.A. 

Mr. W. H. Lascelles 

Mr. A. Francis May 

Mr. H. Neville Munro 

Mr. J. Nicol 

Mr. J. Payne, A.R.I. B.A. 

Mr. Harold Sanders 

Mr. Augustus W. Slater 

Mr. G. Stainthorpe 

Mr. John Tanner 

Mr H. E. Tinslay 

Mr. F. J. Troup 

Mr. Hugh Watkins 

Mr. E. A. Wilson 

Mr. Maurice F. S. Wilson, 
M.Inst.C.E. 

Mr. W. H. Winder, M.S. A. 



Also Mr. H. Kempton Dyson (Secretary) and a Repre- 
sentative of the Central News, Ltd. 

After the submission of the loyal toasts by THE 
CHAIRMAN (Mr. E. P. WELLS), 

Mr. W. E. RILEY (Superintending Architect of 
Metropolitan Buildings and Architect of the L.C.C.) 
rose to propose " The Concrete Institute." He said : 
— Mr. Chairman and gentlemen, A compliment has 
been paid to me in asking me to say a few words on 
the Concrete Institute — I think I may say the toast of 
the evening, without any derogation of those loyal 
toasts which have been received so enthusiastically 
by you all. It seems to me only the other day that 
there was no such thing as the Concrete Institute. 
Indeed, I remember the beginning of this Society when 



THE SECOND ANNUAL DINNER, May 9, 1912 291 

a few well-known experts laid their heads together 
and began to think how coming problems could be 
dealt with, and I see a little the effect of it now before 
me in a healthy and vigorous Society (Hear, hear.) 
I believe you have between nine hundred and a thou- 
sand members, and I congratulate you upon the great 
success you have achieved already. We all well know, 
all of us who have been pioneers — as I have been 
myself on many occasions in life — that pioneer work 
is generally a very thankless task. I do say that those 
who inaugurated this Society had very far-reaching 
thought, because, whether we like it or not, rein- 
forced concrete and concrete generally have come to 
stay. (Hear, hear.) Those of you who have been 
through an architectural training understand the 
problems I have in mind. But I am a man who must 
in the course of nature be nearing the close of his 
official career. The man who is going to make a 
mark in life is the man who is going to show adapta- 
bility and commercial interest. I say this Society is 
the absolute embodiment of that idea. I have heard 
men say, and I think they are misguided, that they 
are sorry some one discovered that putting steel down 
a piece of concrete made it stronger. We know the 
commercial world is not sorry for that ; the commer- 
cial world is going to be glad. I have always felt 
it my duty, so far as I had any idea of the cut -and - 
dried administration of rigid laws, that the proper 
thing for any one to do was to try and make those 
rigid laws elastic by administering them with bene- 
volence. I will remind you that the aims of concrete 
experts have been greatly aided by three or four 
changes in the law. They were based on rigid prin- 
ciples, but you found you could apply them with more 
elasticity than you thought, and that they encouraged 
the application of new materials. I heartily con- 
gratulate you, Sir, and the Council in taking up rein- 
forced concrete which can be applied properly, 
economically, and commercially in buildings in large 
towns. That is, I think, a subject you ought to be 
very proud of. (Hear, hear.) I was recently at 
Rome, and I was glad to ses that the Congress 
of Architects there gave a good deal of time 
and consideration to the question of reinforced 



292 THE CONCRETE INSTITUTE 

concrete. I grant you, at the same time, that the 
conclusion of the whole matter was — no one knew 
how to treat it. Some thought it was papery, thin, and 
expressionless, and so on. But you know the right 
thing will evolve. I think the aims of this Society 
will result in obtaining proper and artistic expression 
by those who are trying*to interpret building materials. 
I feel somewhat diffident speaking to an Institution 
like this about regulations, but the onerous duty has 
been thrown upon me in trying to do something in 
putting the Regulations on a proper footing. Nothing 
will be ideal, but you must try and make them as 
practicable as you can. Any amount of personal effort 
has been exercised to try and make them go. (Hear, 
hear, i It is a very cheap thing to tell me that I 
have been saying two and two make four. I know 
I have said that before on several occasions, but I 
have always had to make two and two four, although 
some people try to make them five. (Laughter. ) 
There is something about the Regulations, and this 
is the only opportunity I have had of saying it before. 
I am deeply grateful — and I believe I am expressing 
the views of those in authority at the London County 
Council — we are deeply grateful for the enormous 
assistance we have had from this Institute in 
endeavouring to pioneer and do something in London. 
Of course, I am not going to say any more about 
them, because they are sub judice, but I hops they 
will soon appear and that we shall know where we 
are. We went through every possible source of in- 
formation we could think of, and tried to get the 
practice of other countries and to codify them for the 
benefit of all. There is one thing I can most heartily 
congratulate you upon, and I do it with a most pro- 
found feeling, and that is of having an eighteen-carat 
man as the outgoing President, Sir Henry Tanner. 
I have known him for many years, both officially and 
in private life. You know your present President 
is an old friend of mine, and an old opponent too. 
(Laughter, i He was an old colleague of mine at the 
County Council, and we all respected and appreciated 
him there, and I am sure you have done the right 
thing in making Mr. Wells President of your Insti- 
tute. (Hear, hear.) I am sure he will not mind 



THE SECOND ANNUAL DINNER, May 9, 1912 293 

my reminding him that we had many strenuous fights 
over the legislation of 1909. I faced nineteen 
opponents there, and he was the nineteenth of 
the opposition, and you know what that was. I 
am sure you will not be surprised to hear that 
the Rules that we then drew up were not too stringent — 
in fact, not stringent enough. You know when one 
speaks about this kind of thing one remembers — and 
I do it with gratitude — although we were opponents 
over the negotiations, I do not think that we thought 
the worse of each other. I speak for myself, and, 
of course, never for a moment was there a bitter 
thought. They frequently told me they were trying 
to gain veracity from an architect, and I tried to gain 
veracity from nineteen men. (Laughter. ) I cannot 
help saying this about the long-looked for Regula- 
tions — they do aim at trying to help you thoroughly 
and to do what you want — namely, to give a fillip 
and to give the benefits of your enormous thought, 
experience, and services to those who are willing and 
anxious to give commercial development to the great 
work which you have been endeavouring to bring 
to fruition. I thank you heartily for giving me the 
opportunity of thanking this Institute for the great 
help you have given me personally in endeavouring 
to make those Regulations such that they will be 
workable and practicable. I give you " The Institute," 
root and branch ; may it prosper, and I couple 
with this toast the name of your able President. 
(Cheers.) 

Mr. WELLS, upon rising to respond, was received 
with cheers. He said : — Mr. Riley and Gentlemen, in 
responding to the toast of the health of the Concrete 
Institute, allow me to thank you for the kind words 
you have said on behalf of that Institute, and also for 
those you have said about myself. Before we go into 
other matters let me thank you, sir, for, as I consider, 
the extremely impartial attitude that you have adopted 
all through the negotiations that have passed between 
the Concrete Institute and yourself in regard to the 
new regulations about to be laid down for reinforced 
concrete, and also at the same time for the fact that 
everything that has been done has been carried out 
in the best of temper. I am happy to say that in 



294 THE CONCRETE INSTITUTE 

every case where suggestions have been made by the 
Institute they have been listened to, and where they 
have been found to be perfectly just they have been 
accepted without a murmur. I have also to thank you 
for the able lieutenant you have chosen to carry on 
the negotiations with this Institute, and more especially 
the one with whom we have been directly connected. 
I trust, •'sir, that in the negotiations you are 
about to carry on with the Local Government 
Board they will be carried on in the same 
spirit as existed between the Concrete Institute and 
yourself. One thought struck me in connection with 
the disaster to the Titanic, and that was that if London 
was in the grip of a very severe frost, and the greater 
part of the mains frozen, what would happen ? Looking 
back on the Great Fire of London, if such a thing 
happened now and half the mains were frozen, the 
conflagration would result in one of the most appalling 
disasters that has ever taken place. The regulations 
to be put forward by the L.C.C. have for their primary 
object the protection of life and property. Personally, 
I shall uphold those regulations throughout, because 
I feel convinced that though they may at the time 
appear a little hard, still they are for the benefit of 
London as a whole. If we put up buildings that are 
as near as passible absolutely fireproof, though it will 
be more costly, still it will be cheapest in the long 
run. Therefore I am of opinion from what I have 
seen and what I have had to do with the 1909 Act 
(steel frame section) that certain portions ought to be 
made more strenuous than in the present Act. I 
hope that if anything is done in the future that certain 
clauses will be added so as to place everything in 
such a condition that no one will be able to alter or 
evade the clauses in any shape or form whatever, and 
whenever we have a building erected in accordance 
with the Regulations we may be perfectly certain that 
if a conflagration takes place that very little damage 
will be done, if any, outside the building where the 
fire originated. There are one or two here who think 
that the Regulations as regards reinforced concrete 
are a little hard, but I think that when the Act is 
thoroughly gone into and applied, that it will be 
found that thev will be beneficial all round. A most 



THE SECOND ANNUAL DINNER, May 9, 1912 295 

interesting paper was read in the last session by Pro- 
fessor Beresford Pite, for which the Council felt 
justified in awarding him the medal. We all hoped 
he would have been here to-night, but unfortunately he 
has to deliver a lecture at the London County Council 
School of Building upon Architecture. Every one, I am 
sure, would have been pleased to see him here to-night. 
The discussion on that paper was a most interesting 
one, and will, I think, eventually lead to some definite 
kind of treatment in concrete and reinforced concrete 
as a whole. I think a special line may be adopted in 
regard to concrete and its treatment, and the Council 
are going to consider the question of offering a yearly 
prize for the best form and treatment in concrete 
design, and I hope we shall have something interesting 
laid before us. This year the Council are going to 
institute educational lectures for the younger mem- 
bers, and I trust they will be attended not only by the 
younger people, but also by some of the older ones 
to give help to the lecturer. I am happy to say that 
the total number of members is nine hundred and 
twenty, and hope before the year is out that the number 
will be a thousand, and that in the next two years or 
so we may see the number go up to two thousand or 
over. (Hear, hear.) With the small number of mem- 
bers we have at present, with an annual subscription 
of a guinea, it takes us all our time to make both ends 
meet. It leaves nothing in hand to make experiments 
with, and we have to depend entirely upon individual 
efforts, and we know perfectly well that when it is 
put upon two or three it becomes a great drain upon 
their resources. So I trust the time is not far distant 
when we shall find that our numbers are increasing 
rapidly, and that with a membership of two thousand 
we shall be able to spend money for the good of all. 
In conclusion, I hope that this Institute may be like 
the material from which it takes its name, and that 
it will increase in strength, numerically and financially, 
and I trust before long that I shall be in a position 
to say that the Concrete Institute has attained a mem- 
bership it never dreamed of years ago, and that many 
we have here to-night as visitors will join the Institute 
and become working members. Gentlemen, allow me 
to thank vou on behalf of the Concrete Institute for the 



296 THE CONCRETE INSTITUTE 

manner in which you have responded to the toast, and 
to Mr. Riley for the kind words he has said. (Cheers.) 

Mr. F. E. WENTWORTH-SHEILDS, M.Inst.C.E., 
Vice-President of the Concrete Institute, in rising to 
propose the toast of ' The Visitors," said : — It is 
with pleasure that I rise at your request to propose 
the health of the guests. It is a great joy to 
us, the members of this Society, to see them here, and 
I hope the pleasure is mutual. Certainly the com- 
pliment — if compliment it is — is mutual. We have the 
honour to-night to offer them hospitality, and they in 
return are giving us a great deal by their presence 
here. They are giving us their sympathy and their 
help and their support. They are giving us the best 
gift that can come from man to man — the gift of 
friendship. A young society like this naturally 
looks with pleasure at its achievements. Young 
people, of course, are sometimes mistaken about 
their own achievements, and inclined to set higher 
value upon them than they should. This reminds 
•one of Mr. George Russell's story of a children's 
party he attended, where there were two dear 
little girls boasting of the things they possessed and 
of the grand things they had done. One little girl 
said, " My hen laid an egg this morning," and the 
other little girl, the daughter of a bishop, threw her 
little chin into the air and said, " Oh, that is nothing ; 
my father laid a foundation-stone." (Laughter.) 
Being a young Society, we perhaps take that view of 
things. We think we have laid a foundation-stone 
" well and truly," and we believe we are building a 
good superstructure upon that stone. We are able 
to point with pardonable pride to our membership, 
which is now nearly a thousand strong. We can say 
that the work which we have done has been useful 
not only to structural engineers, but to builders 
generally. We have suggested rules by which the 
calculations and drawings for reinforced concrete 
designs will in future be simplified. We have been 
able to show how to build structures which will not 
only be strong, but which will last for our generation 
and for many generations to come. We can also say 
with satisfaction that Parliament has entrusted us with 
the work of offering our criticisms and suggestions 



THE SECOND ANNUAL DINNER, May 9, 1912 297 

about the Rules which the London County Council 
have drawn up for the guidance of builders in rein- 
forced concrete. After the kind things that Mr. Riley 
(who is responsible for those Rules) has said to-night, 
you will gather that he appreciates what we have done 
in this direction. I think, sir, that not only may we 
take pride in the little work we have been able to do, 
but we can also feel gratified that our guests have, by 
their presence and acceptance of our hospitality, ex- 
pressed their sense of the useful work done not only 
to the profession, but to the world at large. You 
requested, sir, that speeches should be short, so mine 
will be. But I should just like to echo the hope you 
expressed, that many of those who are guests here 
to-night will be hosts next year, that they will join our 
Society and help in the work we are doing with their 
experience and their advice. In any case, we hope 
this occasion will be by no means the last at which we 
shall have the pleasure of welcoming them. There are 
so many distinguished guests that it would take too 
long to mention them by name, but, as an engineer, 
I should like to say how pleased we are to see the 
President-elect of the Institution of Civil Engineers 
— (Hear, hear) — and I should like to couple with this 
toast the name of Lieut. -Colonel G. E. Holman. I 
give you the toast of " Our Guests," and call upon 
you to drink it with great heartiness. (Hear, hear.) 

Lieut. -Colonel G. E. HOLMAN, in responding, 
said : — Mr. President and Members of the Concrete 
Institute, I am sorry for you that I am in this position 
to-night, but it is not my fault. I asked my friend, 
Mr. Dyson, why, in the face of the galaxy of scientific 
knowledge here to-night as visitors, I should be asked 
to reply for the guests, and the reply was that some 
of the gentlemen had spoken before, or that others 
were going to speak to-night, and therefore it devolved 
upon me as a guest to respond for the visitors. Hence 
I am standing up answering for the visitors. Mr. 
Riley told us one of the best stories to-night — far 
better than the gentleman on the platform. He told 
us how Mr. Wells and a few others put their heads 
together and formed the Concrete Institute. (Laughter. ) 
I always knew my friend was a hard-headed man. 
I have known him for many years, and the longer I 



298 THE CONCRETE INSTITUTE 

have known him the more I have learned to respect, 
admire, and love him. The most scientific of men, 
he is ever anxious to do things on the right lines. 
He is now clamouring that the Regulations should be 
made more stringent. I did not hear Sir Alfred 
Gelder say anything to that, and I did not hear any 
architects clamouring for the same thing. Mr. Wells 
made me anxious, because architects must consult 
engineers from the Concrete Institute. But I am sure 
of this, that anybody who knows our friend Mr. Riley 
will endorse all he has said about the administration 
of the Acts, and that they are administered with bene- 
volence and not with that rigid cast-iron rule, as 
outside the London area. We, as architects, have no 
complaints to make of the administration of the law. 
May I say on behalf of the visitors that I echo all their 
sentiments when I say that we have enjoyed ourselves 
very much indeed, and we are glad to have been 
asked to come. I hope those of us who are not 
members will be asked again next year. (Hear, hear.) 

Mr. HENRY TANNER, F.R.I.B.A., proposed the 
toast of " The President, Mr. E. P. Wells." 

The toast was given with musical honours, and Mr. 
WELLS briefly replied. 

A musical entertainment supplemented the speeches. 
It was given by Mr. Frederick Upton, assisted by 
Miss Doris Clayton and Mr. Edgar Coyle. 

The proceedings then terminated. 



m* 



THE CONCRETE INSTITUTE 

AN INSTITUTION FOR STRUCTURAL ENGINEERS, 
ARCHITECTS, ETC. 



CALCULATIONS IN THE DESIGN OF A 
THRUST BUTTRESS MASONRY DAM. 

By REGINALD RYVES, M.Cons.E., Assoc.MJnst.CE., M.C.I. 

In a paper read before the Concrete Institute on 
March 14, 191 2, there was included a brief descrip- 
tion of the writer's type design for a dam of 
arches supported by buttresses in direct thrust. While 
there is no theoretical objection to the substitution 
of reinforced concrete spans for the arches, the fact jthat 
the whole of the structure is subjected to compression 
stresses points to the probability that for large works 
the most suitable material will usually be plain masonry, 
and the most suitable form for the waterproof wall a 
segmental arch. The following calculations for a 
dam of plain masonry would apply in the case of a 
similar dam made of reinforced concrete, regarded as a 
material, and in such a case the actual stresses allowed 
at different depths in the arched wall and in different 
layers of the buttresses might be varied according 
to the proportion of reinforcement and its distribution 
as designed for the development of high compressive 
strength. A design intended to economise in the 
quantity of aggregate used in the concrete might, in 
the case of a highly stressed reinforced concrete dam, 
have to include the provision of inverts, parallel to the 

u 



300 THE CONCRETE INSTITUTE 

water face, connecting the bases of the buttresses and 
distributing the load upon the rock. Footing out 
or battering out the foundations might in such a case 
involve either the carrying of the bottom ends of the 
buttresses to considerable depths in the rock, involving 
the provision of a good deal of masonry for this 
purpose alone, or such an angular divergence from 
the line of direct thrust as would amount to a secession 
from the principle on which the design is based, and 
might involve the introduction of tensile stresses such 
as those in the bases of reinforced concrete columns. 
The writer does not think that such designs are 
likely to offer economical advantages, though, since 
it may be realised that there would in such cases be 
advantage in departing as little as possible from the 
thrust buttress type, it is as well to recognise designs 
of this character as structurally possible. 

The Advantages of Plain -Masonry. 

As regards expansion and contraction the form of 
the thrust buttress dam is probably as favourable to 
plain masonry as to reinforced concrete, and, apart 
from its permanency and resistance to weathering, plain 
masonry offers one prime advantage and two secondary 
ones, of great significance in the present connection. 
The prime advantage is that it is nearly always and 
nearly everywhere the cheapest material to use per 
unit of thrust intensity. The two secondary advantages 
are, first, that near the bottom of the dam and in the 
ground it is easily put in place, may be safely left at 
different stages of construction, and easily repaired if 
damaged ; and, secondly, that near the top of the 
dam, where, for practical reasons, the dimensions of 
the parts must exceed those found by the calculations 
for strength, its cheapness per unit volume is strongly 
in its favour. 

The following calculations, then, apply to plain 
masonry, and, if they are to apply to reinforced concrete, 
it must be clearly understood that it is reinforced con- 
crete regarded as a material and designed to withstand 
thrust, and that the reinforcement must not pass from 
one buttress layer to another, nor be used to tie dif- 
ferent parts of the arches together, or arches to 



THE DESIGN OF A THRUST MASONRY DAM 301 

buttresses, in such a way that under changes of water 
level or changes of temperature the dam will gradually 
develop stresses other than those which occur with 
plain masonry. It will probably be found that the 
most economical application of steel reinforcement to 
the masonry of a thrust buttress dam will, as regards 
the arches, be radial, and as regards the buttress layers, 
horizontal and transverse, some rods at right angles 
to these — that is, parallel to the water face and inclined 
at 45 degrees — being added in the part of the layer 
which is not covered by the next above it. As regards 
plain masonry, if mass concrete or mass rubble be 
used there must be surfaces of separation between the 
buttresses, and similarly, if the buttresses are built 
of blocks or of coursed rubble, there must be no 
breaking joint where the layers meet, and one face 
of every block should be parallel to the water face 
of the dam. 

THE CALCULATIONS. 

There are only two sets of calculations, one for the 
thickness of the arches, depending on the stress 
allowed, the radius given, and the depth ; and another 
set for the calculation of the width of the buttress at 
any point, the method being the same for the upper 
end, for the lower end, and for any cross -section of 
the buttress layer. 

The Arch Thicknesses. 

For preliminary calculations a rough approximation 
to the thickness of an arch ring subjected to water 
pressure is obtained from the formulas : — 

, ,, . , arch thrust 

arch thickness = 



arch pressure allowed' 
arch thrust = water pressure x arch radius, 



and — 



water pressure in tons ) _ depth below water surface in feet 
per square foot ) ~ ^ 



302 THE CONCRETE INSTITUTE 

For depths down to 80 or 100 feet a fair approximation 
to the maximum pressure in the arch is given by — 

arch pressure = pr x — 
r r 10 

where — 

p = water pressure 
and — 

/' = outer radius. 

For final calculation we may use — 

thickness of the arch ring = outer radius x i 1 — \J r — ^ 

Where it is the maximum allowable stress and p is the 
water pressure. 

This formula may be used if we keep the same 
outer radius and thicken up on the other face. 

If we work from the mean radius we may use the 
formula — 

thickness of the arch ring = *~-\ 1 - * / 1 — ~I- I 

where p is the mean radius. 

Captain Garrett has a table (Table I.) for the 
expression — 



&-J*-*\' 



which reduces the calculation to the working out of a 
series of the equation — 

thickness = kp 

The radius will depend upon the span and upon what 
angle the chord subtends at the centre of the striking 
circle. Captain Garrett has made calculations which 
show that the arch ring which is most economical 
of material is one whiGh subtends an angle of 
1 3 3 34/ at the centre of the circle, assuming the thick- 
ness of the arch to be zero at the top. With an arch 
ring several feet thick at the top a smaller angle 
becomes more economical, 1 20 giving, usually, nearly 
the most economical arch. 



THE DESIGN OF A THRUST MASONRY DAM 303 

The writer has adopted, for his type designs of 
thrust buttress dams, a minimum buttress thickness of 
6 ft. which, with spans of 60 ft. centre to centre, gives 



TABLE I. — VALUES OF "*" FROM CAPTAIN 
GARRETT'S "THEORY OF ARCHED DAMS." 



Depth. 




Maximum Stress 


in Arch Ring a. 




d. 

per S 


9 Tons 


12 Tons 


15 Tons 


jo Tons 


quare Foot. 
0660 


per Square Foot. 


per Square Foot, per S 


quare Foot. 


20 








25 


084O 


— 








30 


1026 


•O748 


•O59O 


— 


35 


1219 


■0886 


•0696 





40 


I420 


•I026 


•0804 





45 


1629 


•II70 


•O9I4 





50 


1846 


•I319 


'I026 


0750 


55 


2073 


•1473 


II4I 


083I 


60 


23II 


•1629 


■1259 


O9I4 


65 


2560 


■I79I 


•J380 


O998 


70 


2820 


•1959 


■I503 


I084 


75 


3094 


•2133 


•IO29 


II7I 


80 


3385 


•2312 


■1758 


1259 


85 


3692 


•2497 


•189I 


1349 


90 


4OI7 


•269I 


•2027 


I44O 


95 


43 6 3 


•2889 


•2167 


1533 


100 


4733 


•3O96 


•23II 


1628 


105 


5*33 


^y 2 


-H59 


1725 


IJO 


55°7 


■353-5 


_'6ll 


1824 


ii5 


— 


•377o 


•2767 


!9 2 5 


120 


— 


•4017 


•2929 


2027 


1 -'5 


— 


— 


•3097 


2131 


130 


— 


"4547 


■3 2 7 l 


2237 


135 


— 


— 


•344 8 


2346 


140 


— 


■5131 


■3629 


^459 


145 


— 




•3818 


2575 


150 


~ 


•5789 


•4017 


2696 



a clear span of 54 ft. subtending an angle of 120 at 
the centre with a radius of 30 ft. The outer radius 
of 35 ft. has been taken for all the arch rings. 



304 THE CONCRETE INSTITUTE 

As the clear span decreases with the depth, the 
angle subtended decreases, and with some materials 
it would be better to begin with a larger angle at the 
top. 

In the design shown in Figs. I and 2, the arch 
stress is 1 5 tons per square foot, this being, in 
each part of the arched wall, the maximum stress as 
calculated by the formula given above. 

Having decided upon the maximum stress and the 
radius, the necessary thicknesses of arch rings for 
different depths can be calculated, a series with 5 -ft. 
intervals being usually sufficient. A study of the 
table so drawn up may suggest what will be con- 
venient increments in thickness. In Fig. 1 the incre- 
ment is one foot. The table being retained as a 
check, the next step is to calculate the maximum 
depth for each of these thicknesses, as follows : — 

The formula for the arch thickness at any depth, 
H, below the water surface is — 







/ 


■»l 


■V- 


2HW) 

- r 




Where- 




R 


= oul 


:er radius 










W 


= weight of 1 cu 


bic foot of water 


in this 


case- 












and — 






1 


ton, 










<7 


= maximum allowable stress 




In this 


case 












Therefo 


re — 


/ 


= l 5 


tons per sq 


uare foot. 






<-vA- 


2x1 

-7 - x 
3 6 x 15 


) 


With 


an 1 


Duter 


arch 

/ 
35 '~ 


. radius of 


35 f t- we 


get- 




= 1 -\A " 


7~FT 

270 




or — 






1 — 










iV'~ 


H" 
270 





Water /ere/ +200 



20 25 ft h/gh from bottom of founc/at/ons 
Span of arch = 60 ft centre to ^centre 
45°S/ope 

Max pressure for masonry ■ fO +on/ft 
Do. Do. for arches m /5 Do. 

Sp. Crav/ty of masonry '2/5 
Outer raa'/us of arch 35 ft. 



/Ve/ght of the 

arch r/ng of wh/'c, 

OPS/? /s a sect/on =/4<*. 



feet tr/ae 




o /020 40 eo so roo 

11 1 

Scale of feet 



Sec f /or, on K-K 

fVe/ght of the part 

of the buttress which arch or buHr .,^ 




Feet fy/bh 



Wo port/on of 
the base of 



base Ef~ 




Pton 
Water /eve/ +200 . 



Fee/ w/de. 





202'u ft. high tronn bo/ form of foundations 
Span of arch -60/7. cen/re /o centre. 

45° S/ope. 
Max. pressure for masonry = /O tons /ft. 
Do. Do. for arches = /5 Do. 

Arch chord subtends /20° ot the centre 
at the top. 
Spec/f/c Gravity of masonry = 2fr 



Scate of feet 



s Feet wr'de 



Section on A-B 



THE DESIGX OF A THRUST MASONRY DAM< 305 
squaring — 



whence — 


H 2t ( I 
1 - — = 1 - + - 
-'70 35 \35 




H 2t ft y 

270 ~ 35 \35/ 


or — 






H 54o/ 270/ 2 



= 15*43/ ~" °'--' 2 - 

This gives the limiting depth, H, for any given thick- 
ness of arch, t, both in feet, as follows : — 



t. 


H. 


6 


84-66 


7 


97"i3 


8 


109*80 


9 


12 105 


10 


132-30 


11 


143-11 


12 


I53-48 


l 3 


163-41 


14 


172-90 


15 


181-95 


16 


19056 


17 


19874 



These figures are altered, each to the nearest whole 
number, or the next higher whole number, which gives 
the length, measured upwards along the water face, 
of each thickness of arch. The thicknesses of the 
buttress layers may be made to suit these lengths, 
so that exactly one, or some whole number of buttresses, 
may abut the springing of each arch ring ; but it 
may be found that this is a needless refinement, and 
that the thickness of every layer or slab of the buttress 
may be the same. In Fig. 1 the thickness is 5 J 2 ft., 
which allows of each arch ring, a foot thicker than 



306 



THE CONCRETE INSTITUTE 



the one above it, being abutted by two slabs ; and is 
a convenient dimension for calculation. 

For some depth from the top of the dam the thick- 
ness of the arch ring will be greater than that given 
by calculation, because there will be some minimum 
thickness depending upon the nature of the masonry. 
In Fig. i this minimum thickness is 6 ft. Towards 
the bottom of the dam the buttresses are closer together, 
the clear span at the bottom of a 200 -ft. dam being only 



\&« 



/7ff. fh/Ch. 



*JZa 



^fYrYi^j^xN^^^ 



<-v3V- 



8 
-26 



-vJ-s*-* 



*B 



200 ff. be/ow cresf. 

Oufer* racf.j5 ? 
Thickness /z 
Oufer rod. 2<4'\ 
Th/cAness // 




Fig. 



26 ft., the pressure in the masonry of the buttresses 
being 10 tons per square foot. If we regard the clear 
span as the span, and contemplate the providing of a 
water face to the buttress, the economical arch will 
have a much smaller radius, and at first sight it might 
seem worth while making the arches near the bottom 
with smaller and smaller radiuses in order to economise 
material ; that represented by the areas marked " B " 
in Fig. 3. But it is better not to do this. The same 
outer radius should be kept all the way down, the 
necessary thickness being given to each arch ring. 
The arrangement as shown in the full lines in Fig. 3 
(at a depth of 200 ft. for 60 -ft. spans, centres) 



THE DESIGN OF A THRUST MASONRY DAM 307 

provides for the maintenance of a water apron which 
is in direct arch thrust across the buttress fronts as 
well as over the spans ; it allows of the buttresses being 
built simply to play the part of buttresses in direct 
thrust, and distinct from that thickness of material 
which has to be made waterproof ; it permits of the 
higher stress in the arch rings changing smoothly 
into the lower stress of the buttresses ; and it main- 
tains the directions of the arch thrusts where each pair 
of arches meet, so that at the water face they all 
meet in one straight line and the thrusts near the 
surface are nearly parallel to one another. A change 
of radius involves a change in the direction of the arch 
thrusts at their springings, it exposes a part of the 



,///? thick. 




-27- 



■33- 



-27-* 



wo ft. beiow crest. 

Fig. 4. 



buttress as a water face, and it introduces there such 
stresses as cannot be allowed unless this part of the 
dam is actually embedded in rock or in very firm 
gravel under a permanent water or silt load. Even 
in such a case economy can better be secured by a 
judicious use of poor material than by a change in 
shape. If, however, there is any doubt as to the 
strength of the material towards the base of the dam, 
a smaller radius may be adopted for the intrados of 
the arch, as shown in Fig. 4, the dotted line. It 
may then be assumed that although the maximum 
stress will not be much reduced near the water face, 
there will be a reserve of less severely stressed material 
behind it. 

For low dams a considerable part of the arch work 
will be of the minimum thickness and in excess of the 
calculated thicknesses. For instance, if with rubble 



308 THE CONCRETE INSTITUTE 

masonry we adopt a minimum thickness of 6 ft. and 
a maximum stress of 10 tons per square foot, we shall 
have a thickness of 6 ft. down to a depth of about 
85 ft., instead of a thickness gradually increasing from, 
say, 2 ft. to 6 ft. In such a case there is, for dams 
not more than 100 ft. or so in height, little or no 
advantage in adopting shorter spans, though for 
materials such as brick, allowing of a small minimum 
thickness, it is an economy to have small spans and a 
small radius. 

The inclination, usually 45 , given to the arches 
results in a crest of varying height. The way in 
which the crest will be finished off will depend upon 
the nature of the materials, upon the amount of " free- 
board " above maximum water level, and upon the 
degree of strength demanded of the crest. The arched 
form is a good one for withstanding the assaults of 
floating timber or ice, and, where the minimum thick- 
ness is considerable, it will probably be ordinary 
practice to stop the building of each course of the arch 
at crest level, after the crown of the course below these 
has reached crest level ; as though the dam had been 
completed with the tops of the buttresses at crest level, 
and the part above this planed off. When the " free- 
board " allowed is considerable, and the spans are 
short, a wall, footed upon the arches, may be built 
from crest to crest, buttressed if necessary. If a road- 
way of considerable weight be provided, its effect upon 
the calculations must of course be taken into account, 
but in the case of a high dam this will be quite small. 

Provision for Elastic Movements. 

The form of the dam allows of a considerable 
amount of elastic movement, but in the case of materials 
which are likely to settle during or after construction, 
or with materials having a low modulus of elasticity, 
it may be desirable to allow for movement by making 
the arch rings with surfaces of separation, conveniently 
made to coincide with a change in thickness, and, 
anyhow, coinciding with the surface of separation 
between two buttress slabs. Then, if a slab moves 
upon the one below it, it will carry its arch and ring 
with it without rupture. 



THE DESIGX OF A THRUST MASONRY DAM 309 

There are several ways of making the joint water- 
tight, two of which may be mentioned. If it be 
desired to maintain a flush water face, one ring of 
brickwork or squared stones set in bitumen and centred 
on the joint may be let in. If the water face is to 
be stepped (which, as suggested by Mr. E. P. Wells, 
may be an advantage in construction as a means of 
holding up the staging) the underhang may be 
carried up as a lip, the groove behind which may be 
rilled with some caulking material, held down by a 
ring of loose bricks, or in some similar fashion — on the 
stuffing-box principle. 

THE DESIGN OF THE BUTTRESS. 

Each pair of arch springings, or common springings, 
will be on the face of a buttress, and, since the water 
face is inclined at 45 , the layers of the buttress will 
also be inclined at 45° — or, generally, the complement 
of the water face angle — in order that the resultant of 
the pair of thrusts from adjacent arch rings may be 
transmitted directly along the corresponding buttress 
slab to the rock. Since, however, each layer or slab 
is held down by the layer above it, and by its own 
weight, and is steadied transversely by the friction of 
roughish surfaces, its cross -section need not be cal- 
culated as though it were a free strut, but only for 
direct thrust. The topmost slab is free, but the load 
on it is very small. 

The Stress upon any Cross-section. 

The way in which the stress upon any layer is cal- 
culated is shown in Fig. 1, in which OPRS repre- 
sents two half arch rings, and the load upon R S is 
the resolved part of the weight of these two half arch 
rings, added t'o half the water load upon two arch 
rings. 

Taking the case of Fig. 1, the buttresses being 
60 ft. apart, centre to centre, the specific gravity 
of the masonry 2J, or ^ of a ton per cubic foot, and 
the layers 5 J 2 feet thick (5 ft. vertically, edge to 
edge), let us first calculate the thickness of the buttress 
slab at the top end, RS. For the purpose of cal- 
culation the arch ring corresponding to this slab, and 



310 THE CONCRETE INSTITUTE 

resting against the front edge, may be taken as 7 1 ft. 
long, and it is, at the depth shown, 13 ft. thick, which 
gives us : — 

Weight of arch ring =13 X 71 X 5 J 2 x 2\ x 3V = 408 tons. 
The thrust upon the front end of the slab is : — 

408 x J2 Q 

- = 288 tons. 
2 

The water load is that due to the pressure at 155 ft. 
depth = -^r- =43 tons per square foot. 

This, acting on the span of 60 ft., gives per span, 
or half the load on two spans — 

4-3 x 60 x 5 \J2 = 1,824 tons. 

The total load is, therefore, 1,824-^288 = 2,112 
tons. Then, if b is the width of the slab at the top 
end where this load comes on it, we have — 

2,112 

- ■ /_ = the pressure allowed = 10 tons per square foot 

5 -J 2 x b 

or — 

2 1 1 2 

b = — 7= = 20/86, say 30 ft. 

IO X 5 ^2 

The following method may be used to check the 
whole series of calculations of top end widths — 

The weight of the arch ring = 13 x 71 X 5 J2 x r V 
The component parallel to the layer is — 

13 X 71 X K V2 x , x — = — '-7 =* = 288 tons. 

J ' D ib 2 16 

The water load is = — v x 60 x 707 = 1.826, 



j 



6 



total load = 1.826 + 288 = 21 14 (\\\ in Fig. 1), 
whence — 

b = 29-99, say 30 ft. 



THE DESIGN OF A THRUST MASONRY DAM 311 

Thus the width of the up-stream end of each slab is 
calculated. 

The next step is to find the width at the foundation 
for every slab. The thrust in R S F E, for instance, 
increases as we proceed from R S to FE, owing to 
the addition of the resolved part of the weight of the 
masonry above it. If W 2 be the weight of the column 
of masonry, E G M X F, then the thrust upon the 
surface represented by E F, and due to this weight, 

will be W 2 x -^, to be added to the resolved part of 

the arch load and water load. There is another way 
in which the total load on E F might be computed, 
namely, by assuming the surfaces of the slabs to be 
perfectly smooth. In that case the load above a slab 
would merely hold it down to the slab below, and the 
load upon the base of a slab would be the resolved 
part of its own weight. Since the slabs are not smooth 
the other method is to be preferred, but it may be noted 
in passing that we get nearly the same results by both 
methods. The effect of the masonry above any section 
may be worked out as a pressure for approximate and 
rapid calculations, but for closer computation the fact 
that the width decreases towards the top may be taken 
into account. 

Having thus found the proper width for every slab 
at the base, we next note that, since the water and arch 
loads remain the same all down the slab, and since, 
further, the shape and size of the overlying masonry 
standing vertically above any section in the right-hand 
half of the figure is the same from the middle vertical, 
A B, to the base ; therefore the area, and the width, of 
the cross -section of the slab remains the same from 
where it cuts A B to where it reaches the rock ; so that 
in the down-stream half of the dam the slabs have 
parallel sides. 

Next consider the portion of a slab between the 
water face and the middle vertical. It is clear that 
since the column of masonry above the section halfway, 
say, is about half the height and considerably less 
than the mean width of the column vertically above 
the section at the base to the left of the middle vertical, 
therefore the increase in width is less than half, and 
the theoretical slab would, if this were the only 



3 i2 THE CONCRETE INSTITUTE 

criterion, have slightly concave sides. Actually the 
sides are made straight, partly for convenience, but 
also because the concave form would increase the burst- 
ing stress at the middle vertical. The shape of each 
slab is, therefore, found by two calculations, one for 
each end ; slabs wholly up-stream of the crest having 
four sides, in plan, and the others having six sides. 
All these widths are marked in Fig. i. 

To Find the Top End Widths. 

Since any underestimate of the weight of the arches 
or the water load affects the whole length of the 
corresponding slab of the buttress, it is important that 
there should be no error on the wrong side at this 
stage. In the design shown in Fig. I a margin of 
safety was given by taking the length of the arch 
ring for the calculation of its weight, as 72-6 ft. This 
gives a sufficient margin to cover the use of a material 
of somewhat higher specific gravity than 2\, and the 
making of the arches a little too thick ; further, the 
margin of safety increases with the depth since the 
real mean radius of the arch decreases. 

The two loads on the up-stream end of a slab are, at 
any depth, H, and for a thickness, T — 

water load = 60 x 7*07 x —r = 1178 H tons, 

arch load = 72-6 x T x 7-07 x —7 X —1= — 22-69 T tons, 

and the — 

total load = 11 78 H + 22-69 T - 

Since the load is equal to the area multiplied by the 
allowable pressure, and the thickness of the slab 
= 7.07 ft., we get the equation — 

11-78 H + 22-69 T = 7'°7 x * x ro 
= 707 x. 

For instance, for the slab marked " 28 " in Fig. 1 — 

H = 147* ft. 
T = 12 ft. 
and — 

11-78 x 147-5 + 22-69 x 12 = 707.1-. 

Whence x = 28-4. 



THE DESIGN OF A THRUST MASONRY DAM 313 

We have taken the water load at the springing of the 
arch, and can safely make this width 28 ft. 

To Find the Bottom Widths. 

The next, and last step, is to rind the widths at 
the bottom ends of the slabs . Take the slab R S F E, 
the loads acting on the cross -sectional area repre- 
sented by F E are — 

(1) The water load, 1 178 H ; 

(2) The arch load, 22-69 T ; and 

(3) The resolved part, in a direction parallel to 
the slab, of the column of masonry standing on the 
two surfaces G E and E F, shown in section in Fig. 5. 

Let 2 be the height of this masonry column and let 
x, already found, be the top width of the slab, and y 
the required bottom width. 

The thickness of the column is 10 ft., and the weight 
of the column — 

= - (x + v) x 10 x —2~ tons. 
2 \ - ' 16 

The resolved part — 

J 2 1 z 

= x x (.v + v) X 10 x —> tons 

2 2 10 

= 022: (.v + v) tons. 

The sum of the loads on E F — 

= 1 178 H + 22-69 T + 0-22 z (x + y) tons, 

and this total load must give a pressure on the element 
of base, E F, not greater than the maximum, in this 
case 10 tons per square foot. Whence we derive — 

11-78 H + 22-69 T + o - 22 z (x +y) = 7 - o7_y x 10. 

For instance, take the element of base marked " 57 " in 
Fig. 1 — 

H = no .1=7 T = 8 and 0=180. 
707V = 1178 x no + 22-69 x 8 + 0-22 x 180 (y + 7). 
= 1295-8 + 181-52 + 39-6 (v + 7)- 

= 39-6v + i754*5?« 
Whence — 

y = 57 ft. 



3i4 THE CONCRETE INSTITUTE 

The Cross Wall. 

Since the width of a slab increases from the top 
end to the middle vertical, AB, Fig. I, and is parallel 
for the rest of its length, there will be a small outward 
thrust in each slab where it crosses the middle vertical. 
Fig. 6 shows how this may be calculated. If the 
arrows a b and a c represent the thrust at this cross - 
section, the resultant, a d, or, actually, some fraction of 
it, is the outward thrust in a direction parallel to the 
water face . 

This thrust, for each layer, being plotted, the cross - 
section of the necessary cross wall, as shown in Fig. 2, 
can readily be calculated. Such a wall is built between 
each pair of buttresses, under the crest. When the 




Fig. 6. 



material of the dam is concrete the same calculations 
of outward thrusts may be used to determine the 
amount of reinforcement needed as an equivalent to 
the cross wall. Such reinforcement, transverse steel 
rods, may, on account of the special purpose which 
it serves, be regarded as a reasonable device in a dam 
otherwise built of plain masonry. The minimum 
quantity should be used, because if any weakness were 
afterwards shown a cross wall could be added. 

Some Further Points. 

In order that the dam may be stressed in the manner 
intended, it is important that the base shall consist of 
inclined faces, one set parallel to the buttress slabs 
and the other set parallel to the water face. 

As regards the position of the top end of each 
buttress, the increasing thicknesses of arch rings and 



THE DESIGX OF A THRUST MASONRY DAM 315 

buttress slabs result in these surfaces being at distances 
from the water face varying from 24^ ft. to 15^ ft. in 
the design shown here. The effect of this is shown 
in Fig. 2, to show the extent of the local adjustments 
needed. In some cases there will be no objection to 
building a small part of a slab resting upon the arch 
ring below it. With other materials, or to suit a 
different order in the placing of materials, it may be 
preferred to make each slab rest wholly on the slab 
below it, with the result that the water face will be 
stepped. This slightly flattens the slope from base 
to crest, and adds a little to the size of the buttress, 
since it involves its being taken a little farther down- 
stream. 



NINETEENTH ORDINARY GENERAL MEETING 

Thursday, October 26, 191 1 

THE NINETEENTH ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296, Vauxhall 
Bridge Road, Westminster, S.W., on Thursday, 
October 26, 191 1, at 8 p.m., 

Sir HENRY TANNER, C.B., I.S.O., F.R.I.B.A., 
F.S.I., etc. (President), in the Chair. 

THE CHAIRMAN (Sir Henry Tanner) :— Gentle- 
men, we have called this special meeting to-night 
because we had an opportunity of hearing Mr. 
Humphrey, of Philadelphia, the Secretary of the Joint 
Committee on Concrete and Reinforced Concrete of 
America, and we therefore thought that rather than 
lose this opportunity we had better call an irregular 
meeting in order that we might hear what he had 
to say on this question of fireproofing. I feel sure 
you all would wish to listen to him and see the slides 
which he proposes to show you. 

Mr. RICHARD L. HUMPHREY then delivered his 
lecture as follows : — 

FIREPROOFING. 

By RICHARD L. HUMPHREY, M.Tnst.CE., M.Am.Soc.C.E., 
President, National Association of Cement Users, Philadelphia, Pa. 

It would seem rather an interesting proposition for 
an American to come to Europe and speak on the 
subject of fireproofing, as the conditions in America 
are so notoriously bad, and give it, as is well known, 



NINETEENTH MEETING, October 26, 1911 317 

the unenviable distinction of having the greatest fire 
losses in the world. These annual losses in America 
are enormous, each succeeding year showing no 
appreciable decrease. Where the per capita losses 
in Europe are reckoned in cents, those in America 
are reckoned in dollars, and represent ten times the 
average loss in Europe. It would seem, therefore, 
rather incongruous for an American to speak on the 
subject of fireproofing in a country that has especially 
low fire losses. However, the occurrence of such 
enormous losses in America has led to the study of the 
subject of fireproofing and fire prevention, and of 
necessity ways and means have been sought to prevent 
the enormous annual destruction of building materials 
by fire. 

In Europe, where the losses are low, the question 
is not by any means so urgent, and perhaps does 
not receive the same attention as in America. 
Nevertheless, observation of the conditions in America 
and Europe leads unquestionably to the conclusion 
that while they are not the same, it behoves, not only 
England but all the countries of Europe to study the 
question of fireproofing, and to study it seriously. 
While it is true there is no annual per capita loss of 
two or three dollars, nevertheless there is no reason 
for any loss at all, and the mere fact that the losses 
are much greater in America is no reason for self- 
satisfaction and absence of efforts to prevent the 
existing losses. That such efforts are necessary is 
evident from the fact that in Europe the growing 
tendency to concentrate enormous stocks of merchan- 
dise in buildings is developing a hazard which is as 
great a menace as it is in America. 

There are in the history of countries three great 
epochs in building construction. The primitive savage 
required some sort of shelter and erected a structure 
of whatever materials were available. As the number 
of structures increased some regard was paid to the 
necessary sanitary conditions, and the ultimate develop- 
ment into great cities necessitated rules and regulations, 
not only as regards the safety of the structure itself 
but also to provide against the loss of life by fire. 

This country is blessed with an abundance of slate 
and stone, and the buildings, therefore, have stone 



3i8 



THE CONXRETE INSTITUTE 



walls and slate roofs. In America there was an 
abundant supply of lumber, therefore the earlier 




Fig. i. — Comparative Area of Four Great Fires : — 

Chicago October 9, 1871 2,125 acres 

Boston November 9, 1 IS72 65 ., 

Baltimore February 7, 1904 140 ., 

San Francisco April 18, 1906 2,630 „ 



settlers built structures of wood, which practice con- 
tinued until more permanent construction became 
necessary. Such permanent buildings, however, were 



NINETEENTH MEETING, October 26, 191 1 319 

surrounded by these inflammable structures, which, in 
time of conflagration, served as a means for their 
destruction. Throughout America there are numerous 
illustrations of small towns wiped out in the course 
of a day, or perhaps a few hours, by reason of these 
wooden structures. 

The construction of buildings always involves the 
question of economy. Fortunately, in America the 
increasing scarcity of lumber and the increasing cheap- 
ness of concrete has led in a large measure to the 
elimination of these flimsy buildings, so in time 
probably the hazard existing in so many cities will 
be removed. 

The subject of fireproofing can best be discussed 
by considering the various features in the construc- 
tion of " fireproof buildings," or buildings of high 
fire -resistance, for no building is absolutely fireproof. 
The term " fireproof building " used so generally in 
America is a dangerous appellation, as it instils in. the 
minds of the occupants a false sense of security that 
often leads to a neglect of those simple precautions 
which are so necessary, and which, if the building 
were labelled " non -fireproof," would be carefully 
observed. Europe believes it necessary to erect build- 
ings of high fire -resistance, and to provide a means 
for putting out a fire of its contents. In direct 
contrast to European practice, in America under the 
lax building laws generally promulgated, buildings of 
a low fire -resistance are erected, the fire departments 
are equipped with magnificent fire -fighting appliances, 
high-pressure water systems, and the country is 
subjected to a great annual tax for the maintenance 
of these expensive fire-fighting systems. 

The annual losses are not by any means represented 
by the destruction of property. In addition, there is 
the annual tax for the upkeep of the fire -protection 
service, and the additional tax caused by the very 
high rates of insurance ; so that, year by year, the 
total annual losses from fire, which are believed to 
be entirely preventable, are represented by a great 
deal more than the two or three dollars per capita, 
which is merely the value of the property destroyed. 

It is most regrettable that this property once 
destroyed represents a permanent destruction — the 



320 



THE CONCRETE INSTITUTE 



lumber and other materials that go into the building 
are permanently destroyed, and in America, where the 
question of the conservation of the natural resources 
is receiving so much careful attention it is felt of 
the utmost importance to study the conservation of 
building materials. There is a great tendency 
throughout America to revise the building laws for 
the purpose of ensuring the erection of better struc- 
tures. Of course, it is impossible to make such laws 
wholly retroactive, and there must necessarily exist 







£4*r sos ro// 



Fig. 2. — The Conflagration, Chelsea, Mass. 



for many years to come buildings which at best can 
only be described as tinder-boxes. 

Another important point is the degree of fire-resist- 
ance. This resistance may be reasonably sufficient for 
ordinary conditions, but wholly inadequate against the 
intense heat from the combustion of a great quantity 
of inflammable materials that may be stored in it. 
The growing tendency to store masses of merchandise 
in buildings makes necessary buildings of higher fire- 
resistance. On the speaker's visits through Europe 
he found instances oT such "fires in buildings ; in one 
case a great warehouse with a large quantity of cotton 



NINETEENTH MEETING, October 26, 1911 321 

and other similar merchandise had been destroyed. 
The building itself was reasonably fire-resisting, but 
insufficient successfully to withstand the intense heat 
generated by the combustion of its contents. It is 
evident, therefore, that buildings, as regards their fire- 
resistance, must be designed with due consideration 
as to the character of their contents. 



Conflagrations . 

The extent of the great conflagrations in San 
Francisco, Chicago, Baltimore, and Boston is shown 
by Fig. 1. The early destruction of the water mains 
by the earthquake crippled the fire service, leaving 
the city at the mercy of the flames, which, with the 
strong wind that was blowing, swept the city, the 
resident section of which was almost entirely composed 
of frame structures. The helpless condition of San 
Francisco following the destruction of the water mains 
was due to the fact that there was no auxiliary water 
supply from the harbour. Most of the cast-iron mains 
were placed in loose soil, and under the shaking of 
the earthquake were readily broken, thereby putting 
the entire water supply out of service. This condition 
has been remedied by the construction of pumping 
stations along the harbour, which will be entirely free 
from damage from earthquakes. 

Fig. 2 is a view of the town of Chelsea, Mass., 
introduced to show how in a few hours the business 
part of a town of considerable size can be entirely 
destroyed. This town consisted largely of frame 
structures, with a few buildings of good construction. 
A strong wind was blowing at the time of the fire, 
which destroyed about one and a half million dollars 
worth of property in the course of a very few hours. 
Fires of this kind, of course, attract temporary notice, 
but they do not attract the same attention as a great 
conflagration that sweeps through the heart of a city, 
and destroys everything except the iron, brick, and 
other non-burnable materials. A typical view of the 
result of such a fire is shown in Fig. 3. 

The city of San Francisco after the fire was a 
powerful lesson on the inefficiency of many forms of 
construction in common use in this country. Other 








i 



4 - 



i VS 



ST 




Q. 3 






S5 
-=•5 



0x1 



o o 



324 



THE CONCRETE INSTITUTE 



great conflagrations have occurred in America, that 
in Chicago being second to that in San Francisco. 
While conflagrations of great size occurred in Boston 
in 1872 and Baltimore in 1904, which destroyed 




Fig. 5. — San Francisco Fire. Failure of Cast Iron Exterior Walls. 



property worth millions of dollars, they were small in 
comparison with those of Chicago and San Francisco. 
In Baltimore the hre-hghting services from Phila- 
delphia, New York, and Washington were practically 



NINETEENTH MEETING, October 26, 191 1 325 

powerless, because in the extreme cold weather which 
prevailed at that time the water supply was of little 
service. It is interesting to note that it is estimated 
the San Francisco fire destroyed, in three days, the 
profits of twenty years in the insurance business. 




Fig. 6. — Guarantors Trust Company's Building, Baltimore, Md. Floors 
and Columns of Reinforced Concrete, Cast Iron Front Enclosure 
and Brick Side Walls. 



It frequently happens after a fire that the walls of a 
structure are still standing and are taken as an evidence 
of the fact that the building has satisfactorily passed 
the conflagration. Often the walls of concrete are not 
damaged by the fire as in the dwelling-house shown in 
Fig. 4, which only requires a renewal of floors, doors, 
windows, and roof to make it habitable again. People 
looked at that building with its walls of concrete, 
and said, " Why, it is a first-class fireproof building." 



326 



THE CONCRETE INSTITUTE 



The value of the structure that remained was perhaps 
10 or 15 per cent, of the cost of the building— 85 or 




90 per cent, had been destroyed. It was not the 
fault of the concrete. The doors, windows, partitions, 



NINETEENTH MEETING, October 26, 191 1 327 

floors, and roof were all of wood, and the building, 
therefore, was far from being " fireproof." 




FlG. S. — Entrance to .-Etna Building, San Francisco. So badly 
damaged by Fire as to have little Value. 



Again, the floors and columns often have a reason- 
able fire -resistance, but the front walls, which are of 



328 



THE CONCRETE INSTITUTE 



cast-iron, are destroyed (see Fig. 5)> ? r the walls ol 
brick wholly or partially collapse. This is illustrated 




Fig. o.-Hobart Building, San Francisco. Structural Granite Columns 



destroyed bv Fire. 



m the Guarantors Trust Company's building of Balti- 
more (Fig. 6), one of the best examples m America 



NINETEENTH MEETING, October 26, 19 11 329 

of the behaviour of reinforced concrete in a serious 
conflagration. Load tests were applied to the floors 




Fig. 10. — Citv Hall, San Francisco. Interior Column in Treasury 
Department critically damaged by Fire. 



after the fire by the Municipal Department of Build- 
ings, and they were found to be amply safe under the 



33° 



THE CONCRETE INSTITUTE 



building laws. In the destruction of the adjoining 
building by fire an opportunity was afforded for the 




73.=: 

_ 'a 
z _ 

? a 



construction of an enlarged modern building, and it 
became necessary, therefore, to tsar down this structure 



NINETEENTH MEETING, October 26, 191 1 331 

which, although in very good condition, did not fit in 
with the new structure. 










Q > 



U X! 



Fire -Resistance of Stone 

Stone is very largely used all over the world for 
ornamental purposes, and it is evident from a study 

Y 



33 2 



THE CONCRETE INSTITUTE 



of buildings in which a severe fire has occurred that the 
stone was almost completely destroyed, and could not be 
replaced without entirely rebuilding the structure. The 
behaviour of granite and hard, dense sandstone in a 
fire is ample evidence that the subject of natural 
building stones should be studied with a view to deter- 
mining their resistance to fire. The United States 
Government has undertaken some studies of this kind 
and has found that the manner in which the stone 




; 



>N~ 





^7 w\ I f\ 


^^ 




t* — 





Fig. 13. — Cowell Building, San Francisco. The Result of Failure to 
provide adequate F'rotection for the Steel Skeleton Against Fire. 



is quarried has a material bearing on its fire -resistance. 
It was found that granite can be so quarried as to 
offer almost 100 per cent, greater resistance to fire 
in one direction than it does in the other. It is evident 
therefrom that in the matter of ornamental building 
stones there is much to be learned from the point of 
view of fire -resistance. In a building of this character 
shown in Fig. 7 the destruction was so extensive 
as to be practically complete, while the spalling of 
the exterior granite facing of the /Etna Building 
(Fig. 8) leaves little of value. When this orna-- 



NINETEENTH MEETING, October 26, 191 1 333 

mental stone is also a structural member, carrying the 
exterior walls as shown in Fig. 9, then, of course, the 
destruction seriously endangers the safety of the struc- 
ture, and when the main interior columns are of granite 
their destruction, as illustrated in Fig. 10, is a matter 
of serious concern, and it shows of what little value 
a column of this character is as a structural member. 




Fig. 14. — Destruction of Reinforced Concrete Floor resulting from 
Failure from Fire of Unprotected Cast Iron Columns. 

If stone is to be used as a structural member of 
a building, it must be fireproofed just the same as 
steel or any other material. 



Protection of Metal. 

In all the great conflagrations in America visited 
by the speaker, it was a common thing to find build- 
ings of steel, which had not been properly " fire- 
proofed," in the condition shown in Figs. 11, 12, 
and 13. While steel may have great strength at 



334 



THE CONCRETE INSTITUTE 



normal temperatures, it has little or no strength at 
high temperatures, and it is evident that steel must 




Fig. 15. — Academy of Sciences Building, San Francisco. Complete 
Failure of Cast Iron Shell. Concrete Core Carrying Load on 
Column. 



be protected from heat. It frequently happens that 
the floor of a structure may be reasonably fireproof 



NINETEENTH MEETING, October 26, 191 1 335 

and constructed properly, but the supports of the floor 
are of unprotected cast-iron or some equally poor 
material, and the failure of the supports causes a 
collapse of the floor. Fig. 14 shows one of the 
floors of a building which has been particularly cited 
as a failure of concrete, but naturally these floors of 




Fig. 16. — Failure of Clay Tile Protection to Steel Column 
caused a Buckling of Column from Heat. 



concrete could not remain in position after the 
supporting cast-iron columns had failed. 

Fig. 15 affords a striking contrast of the relative 
resistance of two materials to fire. In this particular 
building, the Academy of Sciences in San Francisco, 
the architect made a mistake in the calculation of the 



336 



THE CONXRETE INSTITUTE. 



size and thickness of the cast-iron columns, and the 
contractor as a remedy filled the interiors with concrete. 





Z = 
J2 3 
■so 



•r 
5 M 



( * I 



During the San Francisco conflagration the cast-iron 
expanded under the action of heat, cracked, and tailed, 



NINETEENTH MEETING, October 26, 191 1 337 

as will be observed, but the load above was carried 
by the concrete core, which offered greater fire- 
resistance. 

The use of terra-cotta tile represents one of the most 
common methods of fireproofing in America, and it 




Fig. 18. — Buckled Column due to Failure of Wire Mesh 
Plaster Fireproofing. 



is a remarkable fact that architects and constructors 
in general regard burnt clay as an admirable fire- 
proofing material. In a large measure this fallacious 
opinion is based upon the fact that small pieces of 
burnt fire-clay when heated to incandescence and thrown 
into water are not disintegrated. But the clay is not 



338 



THE CONCRETE INSTITUTE 



used in that way — it is used in the shape of a hollow 
tile with thin webs. In the process of manufacture 




CQ - 

en 

■a.3 

v o 

go 

H 

2 p 

•=£ 

CQ 



it frequently happens that the webs of these tiles are 
cracked in the corners, and when columns fireproofed 



NINETEENTH MEETING, October 26, 1911 339. 

with clay tile, as shown in Figs. 16 and 17, are 
subjected to the action of heat, the unequal expansion 
of the exposed or outer face of the tile and the inner 
face against the steel causes a tension which the 
thin webs are unable to resist and they crack and fall 
off. As a result, the tiles are broken away from the 
column, which is then exposed to the heat and collapses 
as shown. 

It often happens that in the construction of columns 
an attempt is made to fireproof by placing around the 
column a metal fabric which is then plastered 






rcrrr;;^..'^^.^;^*7rr^'i...'."'....' ■.;,.. .;...!-.'i-iv:r^ 



L 



J 



r 



£ 



^ 






d. __^ — ^ _~— ~ r 






Fig. 20. — A Satisfactory Protection for Columns consisting of a Double- 
Enclosure of Wire Fabric plastered with Portland Cement Mortar. 



(Fig. 18). In the Fairmount Hotel about one hundred 
columns failed as a result of this method of fire- 
proofing. It frequently happened that the floor settled 
more than a foot (Fig. 19). It must be borne in 
mind that the heat in the building was not very great 
as the hotel had not been completed, and the only 
material burned was a not very large quantity of 
lumber used in its construction. The burning of this 
lumber was, however, sufficient to develop enough heat 
to buckle these flimsily fireproof ed columns. A double 
protection with an air-space between as illustrated 
in Fig. 20 affords a much more satisfactory protection. 
It is in the destruction of such buildings that one 




S v 



c 


-1. 




a 


a 


— 
z 


— 


p 






_, 


Z- 




■J 






X 


















— 


5 


<u 






r* 


V 




s. 


■_ 


-. 




- 


„ 


s 


u 


2 


1 
— 





o 





^Kr " H 




3Pgpi;-sii.. 


■BI*Kgffc ' 








■ - * - H^H 




wv 4 yf 








^K — Jul 


WK^jfeft 



NINETEENTH MEETING, October 26, 191 1 341 

frequently observes the folly of these flimsy evasions 
of the law (see Figs. 21, 22, and 23). 

The method of fireproofing with hollow clay tile, 







O 3 

503 



£3 



previously described, is illustrated in Fig. 17, in which 
the columns have been encased with a thin veneer 
(perhaps 2 or 3 inches thick) of terra -cotta tile. 



342 



THE CONCRETE INSTITUTE 



In this illustration the column has settled 8 or I o inches 
by buckling, and the floor above of concrete has been 
so seriously cracked as to endanger its safety. There 
was practically no available material in the building 
after the fire, as the cost of restoring would have 
been much greater than the cost of entirely rebuilding. 
It is quite usual after a fire to find — where terra-cotta 
tiles have been used — that the lower web has broken 




Fig. 25. — Column Failure resulting from the Destruction of the 
Fireproofing of Wire Lath Plastered with Gypsum. 



off by reason of the unequal expansion above described. . 
This is illustrated in Fig. 24, where a large number 
of tiles, perhaps as much as 35 per cent, of the webs, 
have failed and fallen off, while a larger per centage 
are cracked so badly as to be easily pulled off with the 
fingers. In such a case the only satisfactory remedy 
in the way of a restoration is the entire reconstruction. 
A type of fireproofing for columns which is in 
quite common use in many cities in America, illustrated. 
in Fig. 25, consists of perhaps one thickness of a 



NINETEENTH MEETING, October 26, 191 1 343 

wire mesh, encased with about three-quarters of an 
inch of ordinary plaster. Between this so-called fire- 
proofing and the column are placed pipes and other 
metal structures. As may be seen the column has 
buckled sufficiently to be readily observed ; the 
destruction of the fireproofing is quite rapid. In the 
case of similar structures one could not tell they had 
failed except for a slight bulging in the wall, but 
when the fireproofing was removed as shown, it was 
found that the column had buckled. In a fire of 
sufficient intensity, the action of the heat on the plaster 
is to drive off the water of hydration, leaving an inert 




Fig. 26. — Steel Column Fireproofed with Clay Tile Plastered with 
1 -inch of Mortar. Shows highly objectionable Embedment of Metal 
Conduits within the Fireproofing. 



powder which in itself offers little resistance to the 
conduction of heat to the steel, and there results expan- 
sion and consequent buckling under the superimposed 
load. 

In most building laws, especially the later laws in 
America, there are strict clauses which prohibit the 
embedding of pipes and conduits of various kinds in 
the fireproofing of columns (see Fig. 26). Contractors 
frequently destroy the efficiency of the fireproofing 
in order to get pipes and conduits installed (Figs. 27 
and 28), by breaking away the web in order that the 
tile may be fitted around the pipes or conduits which 
perhaps were not considered when the building was 
designed. These are not usually discovered until a 



344 



THE CONCRETE INSTITUTE 



fire causes the stripping of the fireproofing, as may 
be seen in Fig. 29, showing how the webs of the tile 
in this so-called " fireproof " column failed. In 




y ////^/y/)y/y/////////^ i&///)y^ 




COLUMN IN ATTIC. 

Fig. 27. — Faulty Methods of Locating' Metal Conduits, greatly 
creasing the Efficiency of the Fire Protection. 



de- 



FigS. 30 and 31 may be seen the character of work 
done with hollow tile. The bottom flange of the 
girder is protected with three-quarters of an inch of 




Fig. 2S. — Methods of Breaking Clay Tile Fire Protection to care for 
Metal Conduits, still further destroying the Value of the Poor 
Fireproofing Material. 



solid burnt clay. The effect of heat on such a surface 
is to destroy the anchor holding the tile in place and 
the girder or beam buckles from the expansion due 



NINETEENTH MEETING, October 26, 191 1 345 

to the heat. The under side of the floor tiles " spall " 
or split off under the unequal expansion of the exposed 
web and the upper or protected web. In Fig. 32 the 
fireproofing is covered with 1 inch of Portland cement 







tr^m-^f^^ 



Fig. 29. — Calvert Building, Baltimore Fire. Failure of Clay Floor Tile 
and the Stripping of Clay Tile Column Protection through Expansion 
of the Embedded Metal Conduits. 



plaster, which is insufficient to equalise the defects 
in the clay tile protective covering previously referred 
to. All these methods are flimsy in the extreme, and 
it is an outrage even to permit them to be classed as 



346 



THE CONCRETE INSTITUTE 



" fireproofing." Fig. 33 illustrates quite clearly the 
effect of pipes embedded in the fireproofing. The 
expansion of these pipes has practically stripped the 
fireproofing from the column. Another great diffi- 
culty in this form of construction is the fact that in 
the burning of these clay tiles it is impossible to get 
perfect tiles. They not only warp out of shape and 
crack from shrinkage at the corners where the web 




Fig. 30.— Defective Workmanship Destroying the Protection of Steel 
Girder with Clay Tile. 



joins, but it frequently happens that they are broken 
or otherwise damaged in handling, and the break is 
very badly covered with a flimsy coating of mortar. 
The holes are usually covered with perhaps a quarter 
of an inch of plaster, which either drops off in a fire 
or readily allows the conduction of heat sufficiently 
to soften the steel, causing a buckling of the steel and 
the consequent stripping of the fireproofing from the 
column. 

Attempts are being made to improve this condition, 
and Fig. 34 shows a column fireproof ed with a coating 



NINETEENTH MEETING, October 26, 1911 347 

of 1 inch of Portland cement mortar on the outside. 
This undoubtedly is a better method of construction. 
There is also frequent resort to the practice of filling 
the space between the steel column and the outer tile 
with concrete — a still better form of fireproofing. Even 




Fig. 31. — Defective Workmanship in Fireproofing with Hollow Clay 
Tile. Note Broken Tile, Open Joints, and other serious Breaks 
in Protective Covering. 



with these improvements the webs fail, and it frequently 
happens that this protection of concrete is insufficient 
in thickness to resist the temperature, and buckling 
occurs. 

The view in Fig. 35 is given to illustrate some of the 
fallacies among men who apparently are gifted with 

z 



348 



THE CON'CRETE INSTITUTE 



reasonable intelligence. Let us suppose that the two 
columns shown are of identically the same section. 
The columns were made in long lengths, cut up in 
1 2 -foot lengths and tested at definite ages. One 
column was entirely of concrete, and the other column 



jgggZg tJU-i 



/ finish f*/oor 



■2'P/anL 



Cl nmsn r/oor ri r/owz. 




:. A..,* ■■'&;£&£' * 'fan*. 




W mzmsB 



6 M>/6}K_2/fo 



• P/asfcr 3/oats 



I'fbrttonc/ J \ 
Cement one/ 8 5 HBH 

insfa/ Jbbr/e 



i 



4:^t^^ 



Section A-Q 




Section C-D. 



Fig. 32. — Method of using 1 inch of Portland Cement Plaster on Exposed 
Surface of Clay Tile Fireproofing. Does not Repair Defects in Clay Tile. 

had an additional protection of 3 inches of clay tile. 
The column with the additional protection of clay tile 
naturally stood a higher load test than the column 
without the protection ; the argument was that the 
concrete, protected as it was with the 3 inches of clay 
tile, was the best form of construction there was. 
As a matter of fact, if they had made the concrete 
column of the same section as that protected with tile, 



XIXETEEXTH MEETING, October 26. 191 1 349 

they would have had a still better structure, as has 
been frequently shown. Columns (Fig. 36) with all 
concrete protection are very much superior as to fire- 
resistance than those protected with tile and some 
concrete. 




Yiq. 33. — Bullock and Jones Building, San Francisco. Effect of Ex- 
pansion of Embedded Metal Conduits in Stripping Clay Tile 
Fire-protective Covering from Columns. 



In the San Francisco fire one frequently saw 
(Fig. 37) buckled columns which had resulted in a 
settlement of the floors from 12 to 18 inches ; after 
the fire it became a problem as to how to repair 
them. In some buildings jacks were employed to 



35° 



THE CONCRETE INSTITUTE 



raise these reinforced concrete floors to their normal 
position, the buckled columns were cut out, new ones 





ZZgggg||gjgi^^l 



&ZZ2Z2Z ZZZSSZZ 

'■////////S/'S/S/'/A . 




™?/s*>y///w//,y,'.>,m 



; X 



i 



I 



*■*; 



^ 



o as 



a: 


5 "5 


U 


r ' u 'J 


o 


_• > £ 


a: 


- _ u 









M *. 




















JJ 




- t>e 












A U 



_ fe. f> 



put in and hreproofed, and thus repaired were passed 
by the authorities as being perfectly good. Just what 
the condition of the floor was after having settled 



NINETEENTH MEETING, October 26, 1911 351 

18 inches, and then being pushed back in position, 
no one knows. 

The floor, of course, is an important part of the 
structure ; if the columns are reasonably fireproof, it is 
necessary that the floor shall be fireproof. Fig. 38 
illustrates an admirable fire-barrier for the under side 
of floors which, unfortunately, are not always properly 
designed. Suspended ceilings, i.e., ceilings suspended 
from the under side of the floor, in the San Francisco 
and Baltimore fires proved an excellent shield, and 



1 V \ \ V W U [ 

sea mk^ m^:i:A* -^d 




f* 



\^ 



Y; . ■& :-r.- '- v :-y. t ■. ■:•:■•?. • > \ \ \ - \ v 










Fig. 35. — Fallacious Method of using Clay Tile and Concrete for Protective 
Covering. An All-Concrete Protection would be very much better. 



greatly increased the fire -resistance of the floor. 
Unfortunately, in carrying out this idea, it frequently 
happens that ordinary gypsum plaster is used and 
the ceiling is held in place by a very flimsy anchor ; 
the gypsum loses its coherence at a very low tempera- 
ture, the anchor is destroyed by the heat, and the 
ceiling falls. In the illustration, Fig. 38, all except 
the lower flange of the steel beam is protected with 
concrete ; it will also be noticed that a steel support, 
backed by concrete, springs from the beams and 
carries the floor above. A feature that is bad is the 
fact that the metal anchor which holds the suspended 
ceiling in place is attached to the steel beam. When 



35 2 



THE CONCRETE INSTITUTE 



the plaster protection, which is very thin, is destroyed 
by heat, these anchors or supports become a medium 
for the conduction of heat to the steel beams, which 
frequently are heated sufficiently to cause their collapse. 



r tYtfV tobrrc&r An& L ionxre 






Fig. 36. — Various Methods of combining Clay Tile and Concrete, which 
are in common use, all-concrete being by far the most efficient with 
the greatest Fire Resistance. 



Fig. 39 is particularly interesting, as the anchors failed 
and caused a collapse of the suspended ceiling pro- 
tecting a reinforced concrete floor. This protection 
was unnecessary and in this case was used to secure 
a flat ceiling. The fact that the flimsy character 



NINETEENTH MEETING, October 26, 191 1 353 

of anchor holding the ceiling in place frequently 
renders such a barrier inefficient is well illustrated in 

The building shown in Fig. 41 is of reinforced 
concrete with columns well protected, but the engineer 
who designed this structure destroyed its efficiency 
by placing an unprotected band of steel under the rib 
of concrete. It happened in this particular building, 




Fig. 37. — Monadnock Building, San Francisco. Method of Using 
Jacks to raise Floor to Normal Position for the purpose of re- 
placing Buckled Columns. 



which was a warehouse, that there were great quantities 
of wooden boxes stored there. The heat expanded 
these bands, causing a collapse of the floor under the 
superimposed load. . 

A very common type of construction is shown in 
Fig. 42, where clay tiles are placed against the side 
of the girder, and a very thin coating of hard plaster 
placed over the tile and around the flanges. Of course, 
as far as the interior decoration of the building is 
concerned, this is economical and effective, but for 
fireproofing steel it is of little value. It would be 



354 



THE CONCRETE INSTITUTE 




NINETEENTH MEETING, October 26, 1911 355 




Fig. 39. — Collapse of a Suspended Ceiling due to Destruction of Metal 
Anchor by Heat. 



356 



THE CONCRETE INSTITUTE 



better it these steel girders were entirely unprotected, 
because then the people who occupied the building 




■£ c 
O 



~ — 
'53 5 



would realize that they were unprotected, and would 
exercise precaution to avoid a fire in that particular 



NINETEENTH MEETING, October 26, 1911 357 

building. The thin coating of even Portland cement 
mortar is insufficient protection for the clay tile, and 




sS 



en o 




their efficiency is still further reduced by the defects 
in manufacture and handling. 



35« 



THE CONCRETE INSTITUTE 



It frequently happens that the girders are protected 
with a thin coat of plaster supported on an anchor, 
and the failure of this plaster exposes the steelwork 
to the heat, causing the consequent destruction of the 
floor. 

Fig. 43 illustrates the inefficiency of this method of 
fireproofmg — the tiles have dropped out through the 
expansion of the steel girders ; and another important 



W///S///M///. 




Com pes it ten. — ^ 






GIRDERS. 




fc-Tile 



*i I plaster 



Fig. 42. — Defective Fireproofmy of a Girder — commonly used because 
of Simplicity of Construction for decorative Purposes. 



feature in this view is that the wind bracing, which 
was protected by a thin wall of clay tile, was exposed 
through the failure of the tile and buckled so seriously 
as to impair the strength of the building. 

It generally happens that the roof trusses of a build- 
ing are not protected. The upper ceiling is rendered 
reasonably fireproof, but the steel trusses of the roof 
are not protected, and as a result (Fig. 44) the roof 
affords an entry for a fire from the outside, which, 
through the collapse of the roof trusses, gains access 
to the building. It is just as necessary to protect the 



NINETEENTH MEETING, October 26, 191.1 359 

steelwork of the roof as it is any other part of a 
structure. 

Fig. 45 illustrates another attempt to economise 




> 




z_ 


:/. 










z 


'u 


— 




3 


pq 


<u 


■d 














'3 


5 


U-i 


TS 












rt 



u 


V. 


C/"J 








'u 






1> 


rt 


33 






Uh 


c 


= 


-/. 






X 


^ 










t/j 





c 


3 






-r: 


ttf) 


BQ 


~ 






>. 


r: 


c 







«J 






"Z 


H 







U 





in construction ; in this case the wood floor rests on 
the top flange of the steel girders ; the destruction 
of the contents of the room may destroy the wooden 



360 



THE CONXRETE INSTITUTE 



floor and heat the beams sufficiently to cause their 
destruction. 




£| 

_&< 

u >• 

y: 71. 
1° 



u - 



In most cities there are to be found buildings of 
large size having a reasonable fire resistance, and some- 
times even monumental in their construction, but they 



NINETEENTH MEETING, October 26, 191 1 361 




fi*;** *'; — 1 



— .is/- — 






«« 



KQ 




■Miff la 




?uh 



Fig. 46. — Call Building, San Francisco, showing the complete 
Destruction of Windows by Fire. 



NINETEENTH MEETING, October 26, 191 1 363 

are surrounded by " fire traps." This is particularly 
true in large cities in America, where we have 







Fig. 47. — Warping of Metal Lath Partition through Inadequacy of 
Gypsum Plaster to protect it against Action of Heat. 



•extremely high buildings which, if they were protected 
properly with metallic window and door frames and 



AA 



364 



THE CONCRETE INSTITUTE 



fire-glass windows, would probably act as a barrier, but 
with unprotected plain glass and perhaps wooden 
frames, they offer little or no resistance to a lire. 
The destruction of the tinder-boxes surrounding them 
brings about the destruction of the contents and the 
buildings themselves. 

The building shown in Fig. 46 was notable because 
it was one of the high buildings of San Francisco. 
The steelwork was reasonably well fireproofed, but 




\ 







Fig. 4M. — Asch Building, New York. Efficiency of the sole " Fire 
Escape " to this Building. 



the windows were plain glass, and the contents caught 
fire. With the destruction of the contents came the 
destruction of the fireproofing, and a great deal of 
damage was done to the steelwork. It is evident 
from this picture, which shows a common sight after 
a fire, not only in America but in this country as well, 
that a building with wooden window frames and plain 
glass windows is at the mercy of the fire in adjacent 
buildings. It is a common practice all over the world 
immediately to break the glass in a building that is 
on fire to let the air in, so that the firemen can locate 



NINETEENTH MEETING, October 26, 191 1 365 

the fire. The bursting forth of the flames from these 
windows breaks the glass of the windows of the adjoin- 
ing building, and the fire thus spreads from building 
to building. In this way large areas are destroyed in 
America, simply because the buildings themselves are 
not protected against fire from without . And in the 
buildings themselves you frequently find that the floor 
areas are insufficiently divided up . This is not true 
in England and the Continent, where substantial 
masonry walls divide up the floor into comparatively 
small areas, which is a commendable feature ; but 
in America there are frequently large areas entirely 
unbroken by fire -walls, and if the walls occur they 
are commonly of very low fire-resistance, often con- 
sisting of metal fabric with a very thin coating of 
plaster -of -Paris. Such a type of partition is illustrated 
in Fig 47, from which it is evident just how fire- 
resistant a partition of that kind is, especially in a 
building filled with a large quantity of inflammable 
goods. This particular partition encased the stair- 
way of the building— the means of e~xit in case of fire. 
Similar conditions prevailed in the Asch Building 
fire in New York, where the occupants of the upper 
floors, finding that they could not use the fire-escape 
(Fig. 48) on account of the flames, and could not 
go down on the elevators because the doors leading to 
them were either locked or blocked with machinery, 
jumped out of the windows 100 feet to the street 
below . It was a case of death, and many chose the 
quicker method. It is interesting to note that the 
impact of the falling bodies from that ten-story build- 
ing punched a hole in the vault light of the pave- 
ment. This fire has occasioned a great deal of 
controversy and discussion, particularly in New York. 
Many indignation meetings have been held, and 
spasmodic efforts made to revise the New York 
building laws ; , the dreadful conditions surrounding 
the Asch Building were thoroughly ventilated in the 
technical and local press. But it is a significant fact 
that, standing on the pavement of that ill-fated Asch 
Building, one can see within a stone's throw many 
more buildings that are infinitely worse as regards the 
construction and provisions for safety in case of fire 
than the building in which this catastrophe occurred- 



3 66 



THE CONCRETE INSTITUTE 



It is not only necessary that the floors and columns 
of a building shall be properly protected against fire, 




Fig 49.— Merchants' Exchange Building, San Francisco. Spallmg of 
Enamelled Brick Facing of Light Well and Failure of Clay-Tile 
Fireproofing of Window Frame Separator. 

but it is also necessary that the exterior exposures 
shall be protected. It frequently happens (Fig. 49) 



NINETEENTH MEETING, October 26, 191 r 367 




*sl :'!: 



S 



%> 

^ ^ 



Fm. ^0. — Wells-Fargo Building, San Francisco. Light Well, showing 
Failure of Plain Glass in metal Window Frames. 



368 THE CONCRETE INSTITUTE 

that the windows are of metal frames protected with 
clay tile or some similar fireproofing, and the destruc- 
tion of these windows affords easy access for the 
flames to spread from floor to floor, and leads to the 
destruction of the building. 

Fig. 50 is a view of the light well, Wells -Fargo 




Fig. 51. — An excellent Type of Fire Barrier from Exterior Fires : Metal 
Frame with Wire-Glass. 



Building in San Francisco, where metal frame doors 
and windows with plain glass were used, and under 
the action of the heat the glass simply softened and 
fell down, as may be seen. Of course, this barrier 
was of little value. On the other hand, when the 
window is constructed with metal frame and wire -glass 
of approved type, the glass often softens but remains 
in place, and thus prevents the fire from gaining 



NINETEENTH MEETING, October 26, 191 1 369 

access to the building. Such a type of window is 
shown in Fig. 51, being that of a building adjoining 
one of poor construction, which was entirely destroyed ; 
the excellence of this window as a fire barrier pre- 
vented the destruction of the contents of that building. 
The doors in the view shown in Fig. 52 are pro- 
vided with roll sashes in front, and whilst the falling 




Fig. 52. — Volkman Building, San Francisco. Rolling Fire Doors, Metal 
Frames, and Wire-glass Windows. An excellent Barrier in this 
Conflagration. The broken Windows of the first floor caused by 
the falling Wall of adjacent Building. 



walls cracked the glass of these wire-glass windows, 
nevertheless they proved a sufficient barrier to prevent 
the entrance of the flames into the building itself. 

Fig. 53 is a view of the Pacific States Telephone 
and City Telegraph Building in San Francisco. The 
building was excellent construction, with reinforced 
concrete floors and columns. The exterior was pro- 
tected with metal shutters, metal frame windows, and 
wire glass, but, as too often happens, it had a weak 



37° 



THE CONCRETE INSTITUTE 




Fig. 53. — Pacific States Telephone and City Telegram Building, San 
Francisco. A Building of very high Exterior and Interior Fire 
Resistance. 



NINETEENTH MEETING, October 26, 1911 371 

point. The door in the rear of the building was 
unprotected, and the destruction of that door by the 




Fig. 54. — Building with Metal Frames and Wire-glass Windows 
undamaged by Fire in adjoining Building. 



fire of the surrounding buildings enabled the flames 
to enter, and wrought partial destruction of the con- 
tents, from which it is evident that all parts of the 



37 2 



THE CONCRETE INSTITUTE 



building must be equally fireproof. It is not sufficient 
that three-quarters of the building shall be immune 




from damage from outside, but all the building must 
be properly protected. 

Fig. 54' is a building of reinforced concrete, with 

metal -covered door and window frames and wire -glass 



NINETEENTH MEETING, October 26, iqii 373 

windows, which stood undamaged amid the destruction 
of the surrounding buildings. 

Figs 55 and 56 are interesting views of the result 




- u 



CO 
Wl 



of different methods of protecting valuable papers and 
records from destruction by fire. Fig. 55 shows about 
fifty so-called " fireproof " safes in the rear of the 



374 



THE CONCRETE INSTITUTE 



Palace Hotel, San Francisco, whose contents were un- 
injured. Great care must be exercised in reducing 
the temperature of the interior to that of the exterior. 
Otherwise the contents may be destroyed as the result 
of spontaneous combustion . Concrete vaults have an 
equal if not higher fire-resistance than brick vaults, 
which are the best types. Excellent fireproofs, con- 
sisting of concrete -filled metal safes, are second only 
to the concrete vault. 




1 



I 1 ■ • 

!! !■■■■■■■■■ 

i I ill 9 I f * * "-A 
llMfflf 111! ■ 

- 1111 






Fig. 57. — Mills Building, San Francisco, interior completely destroyed 
bv Fire standing on Shell much damaged. 



A few words in connection with the general question 
of fireproofing. It has been illustrated how columns, 
floors, and windows should be properly protected to 
resist fire from within and to prevent the entrance of 
fire from without. There is no doubt of the tendency 
to-day, with the development of great business enter- 
prises, to erect enormous warehouses. Even where 
the laws of the country tend to limit unbroken floor 
areas there is also a tendency to concentrate in build- 
ings inflammable merchandise in large quantity. 



NINETEENTH MEETING, October 26, 191 1 375 

In Europe an effort is made to build fireproof build- 
ings, and then have an efficient fire service that can 
go quickly to a fire and extinguish it almost as soon as 
it occurs ; this would seem the ideal condition. 

Another matter "In which America is interested is 
that of the conservation of human lives. Much 
greater regard is had for life in this country and on 
the Continent than in America. Each great confla- 
gration or fire in America becomes a greater or lesser 
holocaust in proportion to the number of lives lost. 
Little consideration is given to the matter of safety 
appliances or to providing facilities for the escape 
of" occupants of a building in case of fire. This is 
particularly true in the case of theatres, schools, and 
other places of public assembly. Pertaining to the 
subject under discussion is the provision of safety 
appliances and facilities for the escape of the 
occupants of a building in the case of fire, which might 
be classified as follows : — 

1. Iron fire-escapes. 

2. Encased stairways. 

3. Stairway towers. 

4. Encased fire -towers. 

5. Serviceability and capacity of exits. 

6. Spiral chutes. 

1. Iron Fire-escapes. — These contrivances consist 
essentially of steep iron ladders with narrow iron treads 
of such a character that even under ordinary conditions 
it is almost impossible for any one to descend with any 
degree of speed without serious danger of falling. 
They are generally placed on the exterior of the build- 
ing, passing unprotected ' plain glass windows, which 
readily become an outlet for the flames, thus putting 
the " fire-escape " out of commission. As previously 
stated, such was the condition in the Asch Building 
fire, and rendered the escape of the occupants of the 
upper floors impossible. Fig. 48 clearly shows the 
flimsy character of this structure, rendered useless by 
the flames from the windows surrounding it. 

Fortunately, continual ridicule of these ill -conceived 
contrivances is having its effect in that they are rapidly 
becoming obsolete, and it is the hope of those who 



376 



THE CONCRETE INSTITUTE 




Fig. 58. — Enclosed Stairway, Merchants' Exchange Building, San Fran- 
cisco. Note Failure of Cast Iron Horses and Marble Treads ; also Plain 
Glass Exterior Exposure ; and lack of Fire Wall isolating Stairway 
from Interior of Building. 



NINETEENTH MEETING, October 26, 191 1 377 

are interested in the matter of fire prevention that 
shortly retroactive laws will make such contrivances 
criminal. 

2. Encased Stairways. — Encased stairways are rarely 
protected by fire -walls or fire -barriers of a character 

TOWER PLAN 

WITH 

OUTSIDE HALCONY ENTRANCE 

NO DIRECT COMMUNICATION WITH BC1LDIN0 



Fire Escape 

StmbTower 




Interior 
Of Building 



Tire Door, 
Balcony Solid Floor 

Outside Bldg Line 



Note -Walls cf brick or 
other approved material 
built solidly from foundation 
to at least 36 inches above rooi 
unless building >s fi reproof 
Stair treaos etc must 
be of fireproof material 



Q 



I I 
I I 
I I 



/ 1 1 

( Balcony, floor supports 
— and rails fireproof 

I I 



_ I I 

Elevation 
I I 
I I 
I \ 



Fig. 59. — Fire Escape Stair Tower with Exterior Balcony Entrance. 



to prevent the access of flames from the building, in 
which case the stairway, often surrounding the elevator 
shaft, becomes at once a stack serving as an excellent 
medium for allowing the fire to spread from floor to 
floor and entirely preventing the possibility of escape. 
3. Stairway Towers. — It frequently happens that the 



37§ 



THE CONCRETE INSTITUTE 



stairways are located in a special tower with plain 
glass exterior exposures and without a fire-barrier 
isolating it from the building proper, as illustrated 
in Fig. 58. A fire of any great intensity not only 
readily prevents its utility as an escape for the occu- 



I'l.AN OF STAIR TOWER WITH OUTSIDE 

i:\TKAMT-: COMMON TO TWO NEIGII- 

HOKINI. BUILDINGS 

NO OIIIECT COMMUNICATION WITH BUILDINGS 



Party 



Interior of 
Building 




interior cf 
Building 



Fire Doors 




C-WlNOOW 

Note-Walls of brick or 'Opening in face wall 

OTHER APPROVEO MATER, AL ExTENOS FLOOR TO CEILING 

VESTICuLE FLOC9 OFFIFIEPROOF CONSTRUCTION 
BUILT SOLIDLY FROM FOUNDATIONS Railing at OPENING AS SHOWN 

TO AT LEAST 36 INCHES ABOVE WOOF 
UNLESS Building is FIREPROOF. 
Stair treads etc must bs 
of fireproof material 

Fig. 60. — Fire Escape Stair Tower with Open-Air Vestibule Entrance. 



pants of the building, but renders it an excellent 
passage for the fire throughout the building. 

4. Encased Fire -towers. — The excessive number of 
lives lost in America in recent years has caused serious 
consideration and has led to the adoption of encased 
fire-towers, enclosed with fire-walls, to which access 



NINETEENTH MEETING, October 26, 191 1 379 

can only be had from the exterior of the building. 
In order to enter this fire -tower it is necessary to pass 
out of the building, as shown in Fig. 59, on to a 
balcony and thence through a fire-door into this fire- 
escape, or one may pass into an open-air vestibule, as- 
shown in Fig. 60, and from this into the fire-escape 
through the fire-door. It will readily be seen that this 
affords a much safer and more efficient form of fire- 
escape, having the highly desirable feature of pre- 
venting the access of fire and smoke to the tower and 
enabling people to pass into the tower with safety. 

5. Serviceability and Capacity of Exits. — In the case 
of iron fire-escapes the length of time required for 
the occupants of the building to descend is so great 
as to render them wholly ineffective, especially so in 
such cases where the ladder is so steep as to make it 
necessary to descend backwards. 

In the case of stairways, they are generally designed 
with sufficient capacity to provide exit for a single 
floor in a reasonably short space of time. Often the 
occupants of many other floors above descend to the 
stairway, which becomes over-congested and rendered 
practically useless. In the revision of many of the 
laws in America an attempt is now being made to 
regulate the number and size of the stairways in pro- 
portion to the number of the occupants of the build- 
ing. In the preparation of the New York Building 
Code, some serious study has been made on the subject 
of exits, and the requirements have been so framed 
as to provide sufficient exits to allow the passage of all 
the occupants of a building within a reasonable space 
of time. But America must go still farther if it is 
to provide the degree of safety which every citizen has 
a right to demand, and laws must be so framed as to- 
provide a number of isolated exits in the building in 
order to prevent congestion and arrange the openings 
in such a way that the occupants of all the floors cannot 
pass down the same stairway, but are diverted by the 
construction into a number of stairways. Fire walls 
should be provided in the building so that it would be 
possible in the event of fire on a given floor for the 
occupants to pass through fire-doors on the same floor 
and thus escape from the building in safety. 

When the American people appreciate the fact that, 

BB 



3 8o 



THE CONCRETE INSTITUTE 



important as may be the conservation of their material 
resources, the conservation of human life is much more 
important, with this realisation will doubtless come 
the enactment of strict laws which will adequately 
provide for the safety of its people from fire. 

Perhaps the most critical conditions in the matter 
of fire-escapes are to be found in schools, hospitals, 
theatres, and places of public assemblage. One only 
has to recall the Collingwood catastrophe, in which 




Fig. 6i. — Collingwood, Ohio, School House, showing Faulty Fire 
Escapes and general Flimsy Character of Structure. 



several hundred children's lives were lost through lack 
of adequate fire-escapes and fire-drill. It has always 
seemed to the speaker that it was not reasonable to 
expect small children to exercise any degree of intelli- 
gence or calmness under the frenzy of a fire and to 
expect them to walk out of a burning building with 
order was unreasonable, and that we must provide such 
form of escape as can be used without thought on their 
part. Fig. 61 is a view of the schoolhouse above 
referred to, showing the flimsy character of the 
escape. While no steeper than usually provided, it 



NINETEENTH MEETING, October 26, 1911 381 

is, nevertheless, so steep that one must go down back- 
wards with any degree of safety. 

6. Spiral Chutes. — What should be provided in 
places of this kind are spiral chutes encased in fire 
towers similar to those to be found in the amusement 
resorts on the American continent, where one may 
fall in the chute and land safely several floors below 
without any effort. This provides an absolutely safe 
and speedy means of exit, and the fire-drill in a tower 
of this kind would be a matter of pleasure for the 
children, and such a drill would enable them to act 
promptly in the case of a fire and provide escape in 
perfect safety. 

It is not sufficient argument for the fire-resistance 
of a material to say that the building was fireproof 
because the skeleton of a building stands, as often the 
value of the skeleton is only perhaps 15 per cent, 
of the total cost of the building (see Fig. 57). 

We have in our buildings all over the world marble 
tiles, wainscotting, and various forms of expensive, 
easily destructible finish, and the loss of this orna- 
mental part of a building represents a large percen- 
tage of the entire cost. A material like concrete 
could serve for this character of ornamentation, so 
that the destruction of the contents of the building 
would not involve the loss of its expensive ornamental 
features. 

There seems no doubt but that concrete will play 
a very important role in the future of fireproof con- 
struction, and it was for this reason that the subject 
of fireproofing was selected for this address. The 
Concrete Institute of England and similar concrete 
organisations elsewhere have a very important responsi- 
bility and a very important duty before them. It is 
known that concrete is reasonably fireproof, but not 
much is known about its properties or the methods of 
construction from the view-point of developing build- 
ings of the highest fire-resistance. It is a fact that 
in an investigation of the various concrete buildings 
erected in America, the owners of 2 6" 6 per cent, of 
the buildings reported that they carried no insurance 
on the buildings themselves, but merely insured the 
contents, some even not the latter. 

A structure of concrete when properly constructed 



382 THE CONCRETE INSTITUTE 

is a building of the highest fire -resistance ; unfortu- 
nately, there is a tendency to design the structural 
parts of a reinforced concrete building without pro- 
viding any fire protection. It is just as necessary 
to provide fire protection for the concrete member of 
the structure as it is for a steel, a wooden, or a stone 
member. There is no doubt that different aggregates 
have various rates of expansion, which result in 
different degrees of fire-resistance. 

It behoves the members of the concrete organizations 
not to stand on the superior excellence of concrete as 
a fireproofing material, but to study the question of 
fire -resisting properties and the methods of construc- 
tion, so as intelligently to design structures in which 
the material shall be applied to the very best advantage. 
If conflagrations occur, and buildings of concrete, not 
properly constructed, are destroyed, it reacts against 
the merit of the material. 

The destruction of building materials by fire is 
preventable, and, as previously pointed out, the fact 
that in America the loss is ten times greater than 
in Europe is no excuse why this country, with its years 
of experience and favourable conditions, should not 
exercise the same care to prevent the loss of 33 cents 
per capita of its property every year as America is 
trying to-day to prevent the loss of three dollars per 
capita, by the study of these problems, so that the 
whole world may be benefited. 

The speaker could not address you on the subject of 
fireproofing without paying tribute to the admirable 
work which has been done in England, especially by 
the British Fire Prevention Committee. The effect 
of the work of this committee, which, as you know, 
is a work of love, has been felt especially in America 
and all over the world, and he is very glad to be 
able to testify to its merits and express his apprecia- 
tion and thanks for the admirable work that this 
committee is doing, which deserves and needs support 
and co-operation. The chairman of the committee 
this evening related to the speaker some of the diffi- 
culties that the committee is working under, but he 
believes that, in an institute of this character, the 
study of these problems, the construction of buildings 
that have a very high fire -resistance, is something that 
should occupy your entire time. 



NINETEENTH MEETING, October 26, 1911 383 

America is constructing buildings of concrete, not 
from philanthropy, but because they are economical. 
In the first place buildings of reinforced concrete can 
in many cases be erected more cheaply than of slow- 
burning wood construction. In the second place, the 
insurance companies place a lower rate of insurance 
on such buildings than they do on the other. In the 
third place, the maintenance of the building is con- 
siderably less than in the case of wood or steel, so 
that the owner of such a building is not actuated by 
philanthropy, or a desire to help the cause, but he 
is governed by a dollar and cents proposition, and that 
is why so many buildings are being erected of 
reinforced concrete to-day, and it is a blessing to the 
country that such is the condition. 

Unfortunately, the knowledge of the use of concrete 
is not definite, and there are many buildings erected 
which are very flimsy, and some day we may have 
occasion to regret their erection ; this makes it all 
the more important to study the subject frankly, admit 
the few weaknesses, and try to educate people to 
proper use of concrete both as a structural material 
and as a means of fireproofing. 

In this address the speaker has given you matters 
of interest and thought. It is a matter in which he 
is particularly interested, and hopes to see the Concrete 
Institute join in the study of fire -resistance of concrete, 
because he thinks that is one of the most important 
phases of the study that needs attention at the present 
time. He is very glad to be with you and once more 
meet the members of this Institute. He stated two 
years ago that the National Association of Cement 
Users have a warm regard and high admiration for the 
work which you are doing, and he certainly brought 
to you the friendly co-operation and greeting of the 
American Association. He hopes it may be their good 
fortune to greet the members of this Institute, and 
that there shall always be between the two institutes 
friendly co-operation in the advancement of the proper 
use of this material. 

DISCUSSION. 

Mr. EDWIN O. SACHS, F. R.S.Ed. (Vice-Presi- 
dent Concrete Institute) : — Sir Henry Tanner has 



384 THE CONCRETE INSTITUTE 

suggested that I should propose a vote of thanks. It 
affords me the greatest pleasure to do so, and I think 
that I am echoing the feelings of all present in saying 
that we are extremely indebted to Mr. Humphrey for 
devoting one of the few evenings that he is spending 
in London at the present moment to be with us and 
to give us such a highly interesting " talk."' We are 
also extremely indebted to him for bringing over such 
interesting slides, for the selection presented was 
eminently interesting and instructive. They could not 
have been better thought out and brought together 
if an enormous amount of time had been spent on 
them. (Applause. 1 

Mr. Humphrey, at the commencement of his remarks 
had mentioned the misnomer, " fireproof." The word 
" fireproof " has certainly been a most abominable 
misnomer, and to my mind it has done more to injure 
the progress of true hre prevention than anything 
else. It was a bugbear to that famous fireman Sir 
Eyre Massey Shaw, as far back as 1872, when he 
wrote scathingly about it in the public press, and I am 
afraid whatever has been done since to mitigate the 
use of that horrible word, it is yet all too fashionable, 
although its fashion is fortunately decreasing in certain 
degrees. In the United States, I know, there has also 
been much talk about the use of that particular word 
'" fireproof," and I hope there will be substituted for 
it some day the more suitable word " fire -resisting," 
which is the word that is gradually rinding favour 
in the British Empire. 

The story illustrated in the lantern slides goes very 
far to show that the use of hard terra -cotta slabs 
or " tiles " is not to be recommended in fire-resisting 
construction. In fact, terra -cotta. whether it be tile 
or semi -porous terra -cotta, as now often found on the 
market, is certainly out of place where true fire -resist- 
ance is wanted. Nevertheless, you must always 
recollect that terra-cotta porous solid slabs and bricks 
could be safely used for light partition work and 
the like where only temporary protection is to 
be afforded in dwelling-houses and other domestic 
structures. 

This method of discriminating between different 
degrees of fire-resistance makes me suggest that we 



XIXETEEXTH MEETING, October 26, 1911 385 

should adopt more universally classification between the 
different fire-resistants. We would require for a fully 
protected building far more than for one intended to 
afford partial protection, and, again, more than in 
one of " temporary resistance." Thus, while terra- 
cotta is useful for affording protection in domestic 
buildings and the like, and certainly formed a far 
better partition than the old-fashioned stud partition, 
it is of little use for the more dangerous class of 
buildings. The experience of actual fires in Europe 
and in the United States has gone to show this through 
the thorough investigations that have been made by 
Professor Woolson, of New York, by the Chicago 
Laboratories of the American Underwriters, and also 
by the British Fire Prevention Committee, to which 
Mr. Humphrey had referred. 

Taken all in all, there is, I think, no doubt that if 
you weigh up questions of economy, practice, utility, 
and so on, a properly designed and properly constituted 
concrete will afford the most practical fire-resistance 
that can be got at the present day. And it would 
certainly be most welcome if among the subjects that 
the Concrete Institute took up, were a serious inquiry 
into certain phases of the fire-resistance of concrete 
which has not yet been fully entered into. 

Mr. Humphrey said, however, and rightly said, that 
even concrete structural features require fireproofing. 
A reinforced concrete beam, with its metalwork 
partially protected with half an inch or an inch of 
concrete, is not a fire-resisting structural feature of 
any very great moment. Experiment and experience 
have both shown that for a practical beam of anything 
over 10 feet span, at least 2 inches of protective 
concrete, of proper aggregate, are required to protect 
the steel members. Should this not be possible, or 
practicable to obtain, or should in very large beams 
only 2 inches be given, then we must think of pro- 
tecting that actual beam with another fire-resisting 
curtain or coating. Whether that coating be in the 
form of a plastic material, an asbestos plaster, or 
what I believe is being used at the present moment 
in the United States, a kind of pumice covering or 
cinder covering, no matter, but some kind of covering 
is certainly required for these very large reinforced 



386 THE CONCRETE INSTITUTE 

concrete girders, which show all too little protection 
at the moment to their metal members. Where the 
fashion has come from of not protecting the metal 
sufficiently I do not quite know, but I am afraid 
it comes, to a certain extent, from France and 
Belgium. 

Only recently abroad I was looking over some very 
large concrete warehouses, where the concrete covering 
of the metal rods was chipped off in places, and it 
was scarcely half an inch thick, whilst in the panels 
you could literally, with the naked eye in the sharp 
sunlight, see each row of reinforcing material, and on 
being given permission to work at it a little with my 
penknife, I found that in these great buildings the 
protective covering was little more than a wash, it was 
somewhere between one-eighth and a quarter -inch. 
And this was in some of the newest, largest, and most 
extensive warehouses of the Continent. 

As to the general features of fire protection in the 
United States, as compared with those in England, I 
think we have one very great advantage in this 
metropolis. We limit the cubic extent of our build- 
ings, and, until recently, this was most strictly enforced. 
Now, with the tendency to build large stores and 
larger workshops, powers have been obtained through 
Parliament to extend those limits to a certain extent, 
and they are being so extended in many instances. 
A note of warning should here be sounded that the 
limits should not be extended too liberally. 

The other great safeguard in London is certainly 
our height limit, and the fact that in our new high 
buildings the two floors and the roof have to be of 
fire -resisting construction. 

Then, our other great safeguard is the splendid way 
in which the regulations as to party walls have been 
perfectly enforced ever since 1853. On top of these 
structural safeguards, we have one other safeguard 
which plays an important part. I do believe that we 
pay more attention to the safety of the life of the 
human being in this country than perhaps in any 
other country, including the United States. Life counts 
for more. With this provision for the safeguarding 
of life, we have received many regulations specifically 
intended, in the first instance, to save life, like the 



NINETEENTH MEETING, October 26, 191 1 387 

provision of exits, staircases, and so on, and these all 
make towards better building construction as a whole. 

In those four points I think we have a certain 
advantage over your great continent, and it is to be 
hoped that some of these points, which I know Mr. 
Humphrey has been studying in England and on the 
Continent, will be embodied in that great Building 
Act in New York which is now being worked upon, 
and drafts of certain portions of which the British 
Fire Prevention Committee and myself were honoured 
with for our observations a short time ago. 

We have to thank the United States, however, for 
a great many things in the development of our building 
construction of late years. I think we have to thank 
them largely for a number of the better constructed 
floors that we have got over from the United States, 
quite a number of doors, and also for the more general 
use of wire glazing. 

I would ask you, gentlemen, to accord our friend 
Mr. Humphrey our very best thanks for coming over 
and speaking to us in such a very delightful and 
interesting manner. (Applause.) 

Mr. E. FIANDER ETCHELLS, F. Phys. Soc, 
M.C.I. (Council) : — Mr. President and Gentlemen, I 
am pleased again to meet Mr. Humphrey after the 
interval of absence. I am also gratified by and 
interested in the lecture this evening. The meeting 
has been described as an irregular one, but it has been 
very interesting all the same. 

With regard to the low loss of life in London, I 
think it is largely due to the provision of suitable 
means of escape, quite apart from the question of the 
construction of the building, and I have generally 
found that the loss of life has been due to the contents 
of the building — for instance, the Clapham Junction 
fire, and also the one last night in the Walworth Road. 
No matter how fireproof a building may be, the build- 
ing owners (of course, for the best of reasons ) cram 
as much goods into the shop as possible, so that the 
passages are only 2 or 3 feet wide. Take, for 
example, the ordinary newspaper shop, such as that 
in which the fire occurred last night, or the Clapham 
Junction fire. The position of affairs is such that, 
when one lot of goods takes fire, it immediately spreads 



388 THE COXCRETE INSTITUTE 

to the next lot. The question of getting fire protec- 
tion for the contents of the building is so intimately 
connected with the question of rental values, the 
desirability of getting the most out of any given 
premises, that absolute fire protection is, I fear, almost 
impossible. 

With regard to the question of " fire-resistance," 
as a term, instead of " fireproof," it might be pointed 
out that, in all recent legislation, fire -resistance is 
spoken of, and not fireproofing. It is generally 
recognised now that fire -resistance itself is merely a 
relative term, and you have only to get a high enough 
temperature and any material will melt. The highest 
temperature commonly obtained is about 4,ooo : C. in 
the electric arc. There are very few materials would 
stand that ; but we need not go to high temperatures to 
get danger. Take ordinary iron or steel, at about 
7oo : F., a temperature which is not much above the 
lowest visible heat. At that temperature steel loses 
about 30 per cent, of its strength. Immediately after 
that there is a very great loss of strength, and it is 
there that the danger occurs. Suppose a building be 
designed with the safety factor of 4, the calculated 
working stress being, therefore, one-fourth of the 
ultimate. The secondary stresses, which may not 
appear in the calculation at all, may be as high as 
100 per cent, of the nominal working stress. You 
have, therefore, the actual stress equal to about half 
the ultimate, and then as soon as we mount to the 
increased temperature, the ultimate strength having 
been reduced by half, you have got disaster at once, 
and the building down upon the ground. 

With regard to some of the illustrations this evening, 
I am very pleased to notice a great number of them 
where the pillars had failed with an absolutely central 
load. There have been many conjectures as to what 
extent in buildings the theoretical assumption of 
central loading would approach the truth, but we have 
had quite a number of instances of central loading, 
and that should give us all the greater confidence in 
dealing with our calculations. 

Another noticeable feature was the improved strength 
of wired glazing, another instance of the advantages 
of reinforcement, for it is nothing else but reinforced 
glass. 



NINETEENTH MEETING, October 26, 1911 389 

Another feature noticeable in the illustrations was 
the superior advantage of the solid casing against the 
hollow tiling, and I am of opinion that part of the 
expansion in the hollow tiles is not only due to the 
expansion of air in the casing, or behind the tile, but 
is also due to the increased longitudinal expansion of 
the tile itself. As the length is limited from the 
ceiling to the floor, and as the tiles must expand in 
length, they bulge out just as railway lines have been 
known to do in hot weather. 

Moreover, the solid tile has a better chance of being 
more uniformly heated. In the case of the hollow 
tile, there is probably a greater difference of tempera- 
ture between the surface in contact with the llame 
and the surface in contact with the steel. This would 
cause a relatively greater camber or bulging of the 
outer face. 

After seeing the illustrations, I am rather satisfied 
that we have in this country certain limitations as to 
the floor area and cubic extent. It does not follow, 
however, that the limitations should inflict great hard- 
ship on building owners, for there is practically no 
limit to the cubic extent of warehouses that may be 
erected and still comply with the regulations, pro- 
vided that proper double iron doors and party division 
walls and floors are constructed in accordance with the 
Amended Acts. 

It must be acknowledged that the smaller percentage 
of loss through fire in Great Britain does not neces- 
sarily indicate any greater constructive skill on our 
part. The lesser loss is a consequence of the greater 
value which we place on any human life, irrespective of 
nationality, and it is also a consequence of our system 
of land tenure, whereby the buildings become the 
property of the freeholder upon the expiry of the 
tenant's lease. The freeholder naturally insists upon 
permanent forms of fire -resisting construction. 

In conclusion, I would like to ask a question of 
Mr. Humphrey. Mr. Sachs has told us that he con- 
siders 2 inches of protection the minimum for 
reinforced concrete. Air. Sachs's experience has been 
largely in England and various parts of the Continent. 
Mr. Humphrey's experience has been gained in 
America. I would like to inquire what is his personal 



390 THE CONXRETE INSTITUTE 

opinion, as to what would be a good amount of cover 
or protection in the case of pillars, beams, and slabs 
respectively ? 

Finally, gentlemen, with regard to the vote of 
thanks, I think you all know, and I am sure Mr. 
Humphrey knows, that I most heartily second that vote 
with the greatest possible pleasure. (Applause.) 

Mr. WILLIAM G. KIRKALDY, Assoc. M. Inst. C.E., 
M.C.I (Council) : — I should like to thank the 
author very much for the very interesting address 
he has given. It is a very great pleasure to 
see Mr. Humphrey over again in this country. 
I had the great pleasure of meeting him some 
time back and comparing notes together. I have 
been very interested in the slides he has shown. 
It has been very striking to see the effect of the fire 
on terra -cotta tiles. I thought previously that terra- 
cotta would make a very fair protection, but evidently 
that is not so, seeing so many columns very bulged. 
Incidentally I might mention they are very pretty, the 
symmetrical shape they took, bulging in so many 
places ; they are very symmetrical. But I think terra- 
cotta should be avoided after so many cases as we 
have seen on the screen to-night, and that concrete 
is a far more promising thing. 

I thank Mr. Humphrey for his address. 

Mr. E. P. WELLS, J. P., M.C.I. (Treasurer) 
(Council) : — Mr. President, I am personally very much 
obliged indeed for the most interesting address that Mr. 
Humphrey has given us to-night, and there is one thing 
that 1 must congratulate him upon and it is this, that 
he has absolutely convinced me of the wisdom of what 
the London County Council have done in passing the 
1909 Act, with this difference, that the Council, in 
certain stringent provisions they laid down in that Act, 
are not stringent enough. Now Mr. Humphrey has 
proved that, especially in column construction and 
the encasing of the same with fire -resisting materials, 
if you want to absolutely protect a steel stanchion 
from danger in case of fire it must be thoroughly 
encased in concrete. It ought, in my opinion, to be 
covered with a minimum thickness of 3 inches, and 
that in no case should any casing of what is known 



NINETEENTH MEETING, October 26, 191 1 391 

as " plaster partition " be permitted ; that it should 
in all cases be concrete, or, failing concrete, then 
brickwork set in cement. That is proved by the illus- 
trations he has given, showing the effect of fire on 
steel stanchions, especially where they have been cased 
with tiles. Of course we know perfectly well that 
where concrete is filled in between the tiles and the 
body of the stanchion, in 99 cases out of 100 
it is of a very inferior nature, but in the casing of 
stanchions, to make them absolutely fire -resisting, or 
as near fire -resisting as it is possible to do, the 
concrete ought to be of a very much richer nature 
than is generally used ; the aggregate should be of a 
very fine description, not larger than about half an inch. 
Since the passing of the 1909 Act, I have seen 
stanchions encased with an aggregate made from 
broken brick and other similar materials, which had 
been passed through a 2 -inch ring and without any 
sand. Now, in a case of this kind — and it is very 
common — it becomes an absolute physical impossi- 
bility with a concrete of such a nature to make it fire- 
resisting, because it is extremely porous. Such being 
the case, it follows that heat readily finds its way on to 
the metal. This applies not only to stanchions, but 
also in the casing of steel beams. 

If it is necessary to get a concrete of a good fire- 
resisting nature, it is absolutely essential that a fine 
aggregate should be used. A large aggregate that 
would fly and sprawl will, when crushed to anything 
below half an inch, make a good fire-resisting concrete, 
and will not in any way fly. 

To show how easy it is to court disaster even with a 
very carefully worded Act of Parliament, I have seen 
cases where wood firring has been put underneath steel 
joists so as to regulate the distance between the 
surface of the steel and the shuttering, and this has 
been allowed to remain in after the joist or girder has 
been surrounded with concrete. Now should a fire take 
place in a building where this wood firring has been 
allowed to remain in, one knows perfectly well that 
it would take a very short time, if the girder were 
subjected to great heat, before it would collapse. 

There is another point that I was very pleased to see 
taken up by Mr. Humphrey, and one which I have 



392 THE CONCRETE INSTITUTE 

adopted for years past where it has been found neces- 
sary to use cast-iron columns in combination with 
reinforced concrete construction, and that is to rill 
the columns with concrete. Wherever possible, I 
always, in addition to the concrete, put in some steel 
reinforcing in the shape of rods. It not only 
strengthens the concrete, but it binds the same together 
if the column be not filled at one operation. I am 
very pleased to see Mr. Humphrey has so fully con- 
firmed what I have done, and that is by proving by 
one of the slides that where a fire has occurred in a 
building where cast-iron columns have been rilled with 
concrete, that the concrete core has carried the whole 
of the load even when the cast-iron has been seriously 
damaged. 

The time, Mr. President, is now getting late, and I 
have no doubt that others will wish to say a few words, 
but before I sit down I have again to thank Mr. 
Humphrey for his most interesting lecture this 
evening. (Applause.) 

THE CHAIRMAN (Sir Henry Tanner i : I will 
now put the vote of thanks which has been moved by 
Mr. Sachs and seconded by Mr. Etchells, and in doing 
so I should like to express my indebtedness to Mr. 
Humphrey for the very interesting observations that he 
has made, and also for the thoughts that he has raised. 
These slides, which he has shown on the screen, have 
been most instructive and far more impressive than 
anything any one could tell us as to the way fire has 
treated these different structures . I agree also with 
what has been said about tile casing. I never did 
like tile casings, and I have never used them, and the 
results of these fires have shown how very little they 
are to be relied upon. I have great pleasure in putting 
this vote of thanks, and I am sure you will pass it by 
acclamation. (Applause.) 

Mr. HUMPHREY :— Mr. President, the speaker 
does not wish to detain you long by unduly extending 
the remarks, but certain interesting points have been 
raised in the discussion. The subject of fireproofing 
is almost inexhaustible, on which one could talk for 
hours at a time. The speaker has endeavoured in the 
course of an hour to bring to your attention, in a way 



NINETEENTH MEETING, October 26, 191 1 393 

thai would probably leave an impression, some of 
the essential features of fireproofing from his point of 
view — the result of the experience which he has had. 
Mr. Etchells brings out some points opening up a 
held of discussion which is most interesting. In 
England, as already stated, your Fire Prevention Com- 
mittee has been engaged in studying the relative fire- 
resistance of materials ; in America, in Germany, and 
in Austria test houses have been made and small 
floors have been constructed, fires built under them, 
both with and without load, and tested. They have 
been most excellent in developing the relative fire- 
resistance of various structural materials and the 
comparative value of various forms of fireproofing. 
The city of New York had a requirement which com- 
pels new systems of fireproofing to undergo such a 
test. Almost every system tried failed on the first 
test, but in the test the patentee acquired a certain 
amount of wisdom and the second test was passed. 

We must first know the relative fire-resistance of 
materials ; second, the relative fire-resistance of 
concrete with various aggregates ; but the most im- 
portant thing that we do not know is the behaviour 
of a structure, as a whole, in a conflagration. If you 
can conceive of a warehouse of large extent, with 
contents of wall-paper or cotton, and consider that a 
fire occurs in the centre, an intense heat is generated — 
what happens to that structure ? The parts immediately 
in proximity to the fire are expanded by the heat, which 
free expansion is resisted by the cooler masses that 
surround, and the result is that the great force exerted 
by reason of the expansion inevitably strips off the 
fire protection on the steel, or whatever the structure 
that carries that load. 

Now, in the speaker's judgment, the most important 
thing in the building is the study of the expansion 
of the structure as a whole, and the value of taking 
a large floor area and breaking it up into 5,000 
square feet or 100,000 square feet is that you reduce 
the amount of area that can be subjected to that 
expansion. 

Mr. Etchells has asked what amount of protection 
is necessary in the case of a reinforced concrete 
column. It is frequently the practice to put 2 inches 



394 THE CON'CRETE INSTITUTE 

of concrete on the outside of the reinforcement and 
i^ inches on girders and three quarters of an inch on 
slabs. 

Now, that amount of insulation is just as valuable 
as 5 inches of concrete as fire protection. It depends 
entirely on how the steel in the structure is insulated. 
If in the course of construction there is a direct 
connection by metal that brings the steel in contact 
with the air, no amount of protective coating will 
protect that metal because the heat is transmitted 
through the metal, and its expansion strips the fire- 
proofing. 

The speaker is of opinion that the best way to 
protect a column is to surround it with a metal fabric 
which will distribute the expansion of the concrete, 
and then, perhaps, a lesser thickness than 2 inches 
is desirable. But you cannot lay down a hard-and-fast 
rule as to how thick it should be. A building which 
contains merely office furniture does not require as 
much protection as a warehouse in which a large 
quantity of inflammable goods is stored, and you must 
gauge the amount of protective coating on the 
structural member by the character of the contents 
of the building. The American Joint Committee on 
Concrete and Reinforced Concrete have prescribed 
2 inches on columns, 1^ inches on beams and girders, 
and 1 inch to f inch on slabs, and the speaker thinks 
that is quite sufficient. 

The speaker's experience in studying the penetration 
of heat in fires and in the tests which were made 
by the Government of surfaces subjected to heat, is 
that in ordinary concrete and with temperatures that 
are well beyond what might be expected in an ordinary 
fire, the penetration of heat rarely exceeds three- 
quarters of an inch, and in most conditions it only 
penetrates perhaps half an inch. 

This brings up a subject which has been frequently 
discussed, and that is the value of material like lime- 
stone as an aggregate in concrete. Now, it is a fact 
that if you keep the limestone aggregate away from 
the surface and you have a protective coating of 
silicious mortar, the limestone is just as good a medium 
for a fire -protective coating as other material. It 
is infinitely better than granite or gravel. But if 



NINETEENTH MEETING, October 26, 191 1 395 

the limestone is subjected to the direct action of the 
flames, it is decomposed by the driving off of carbonic 
acid gas, and if water comes in contact with that lime 
it hydrates and disintegrates. 

We have a method of fireproofing which is being 
gradually developed in America, in which cinders are 
used as the aggregate of concrete. Of course, there 
are all sorts and conditions of cinders, and the defini- 
tion of the word " cinder " itself is very elastic and 
ambiguous. But if you take cinders as meaning 
clinker, and not the ordinary sort of ashes from the 
furnace — that is, clean and free from sulphur— and 
mix that up with cement, you get a material of very 
high fire -resistance, and if that material is put round 
as a protecting feature for a column or a girder you 
get a covering of superior excellence. 

Recently the speaker has inspected buildings in 
which, through the action of sea water and salt air, 
the embedded steel has been so corroded that there 
was only a brownish trace of perhaps what was 
originally a f-inch bar, of steel. That is a 
serious problem which we must study. It is just as 
important as the fire -resistance of the concrete. A 
study of the structure reveals the fact that the 
contractor in placing the reinforcement used in a 
^-inch bar of steel, the end of which was exposed ; 
corrosion started at that exposed end, and as soon 
as it struck the main reinforcement the corrosion or 
rusting commenced and caused a swelling, stripping 
ofi entirely the protective coating of 1^ or 2 inches 
of concrete. It is a fact that the floor above is still 
standing, but fortunately for the structure, the beam 
was a very deep one of short span, and by reason 
of an arch action there was sufficient strength to carry 
the load. 

There was another cause for the corrosion of the 
steel. The contractor used a gravel which consisted 
of a mixture of soft shale and limestone. These 
particles of material, having a very high absorption for 
water, came in contact with the steel and became 
excellent mediums for the conduct of moisture and of 
carbonic acid, which, therefore, resulted in the corro- 
sion. That brings to mind that you must use as aggre- 
gate for concrete materials which have low absorption 

cc 



396 THE CONXRETE INSTITUTE 

— the harder and denser the aggregate, the better is 
the concrete. 

The protection of the embedded metal with a 
reasonable thickness of concrete is desirable, but the 
speaker believes that the problem of keeping the con- 
tents of a building segregated in small units of very 
small floor area — of not more than 5,000 square feet— 
with properly protected fire-doors and fire-walls, is 
the main essential in a building. Where you have a 
conflagration, it does not matter how thick the pro- 
tective covering is if you have an enormous flat surface 
subject to heat action, the expansion of that surface 
will undoubtedly strip the protective coating. The 
expansion in clay tile is not so much the expansion of 
the air, which is made possible by dsfects in the tile 
itself, but it is the fact that terra -cotta has a much 
greater expansion under heat than concrete, and that 
very thin web of perhaps three-quarters of an inch 
expands very rapidly, and the lower web expands less 
rapidly, and as a result of this intensified expansion 
the web simply drops off. 

The speaker believes that the points raised by Mr. 
Sachs are being considered largely in America. We 
do lose a great many people by fire, and there is 
apparently a great carelessness, but you must bear in 
mind that we have a condition that is the outgrowth 
of a very young country. While England reckons her 
civilisation by thousands of years, America reckons 
hers by hundreds, and we have barely outgrown the 
frame houses of the pioneers who settled America, 
and it is the gradual elimination of these frame build- 
ings, that are such a menace to our population, that 
is commanding our attention. The law is getting 
more strict, and it is in this study and this evolution 
that some of the good things that Mr. Sachs has 
stated have been evolved. We still have many bad 
things, and we have looked to Europe and to England 
for a great deal of help in the solution of this very 
important problem. 

The meeting then terminated. 



o^7 



THE CONCRETE INSTITUTE 



AN INSTITUTION FOR STRUCTURAL ENGINEERS, 
ARCHITECTS, ETC. 



REINFORCED CONCRETE IN SOUTHERN 
NIGERIA. 

By H. C. HUGGINS, M.Soc.E., M.C.I., District Engineer P.W.D., 
S. Nigeria, W. Africa. 

Although reinforced concrete has been much dealt 
with during recent years, yet the writer does not think 
that the subject has been touched upon from a tropical 
point of view to much extent. 

The following brief notes on some such work lately 
carried out by him in Southern Nigeria might not 
be without some practical interest. 

Climatic Effects. 

The climatic condition of the country, especially 
around the region of the Niger delta, is one of extreme 
humidity from June to November, whilst the earlier 
part of the year is excessively dry. Variation in 
volume due to such changes is not found to seriously 
affect a moderate concrete after setting has once taken 
place. Rich mixtures should be avoided as much as 
possible in a country of this nature, where there are 
periods of great heat followed by excessive dampness. 
Great care must be exercised that the intense heat of 
the sun does not cause the material to set too quickly. 
In order to keep the surfaces of reinforced concrete 

DD 



398 THE CONXRETE INSTITUTE 

slabs, girders, etc., moist, and protected from the 
sun's rays during the setting process, a 2 in. thick 
layer of sawdust evenly spread over them and watered 
twice a day has proved an excellent protection. 

Reinforcing metal must be immersed in water or 
thoroughly damped before being embedded in the 
concrete if it has been exposed to the sun's heat 
for any length of time before being fixed — often an 
unavoidable occurrence — otherwise the portion around 
the reinforcement sets too quickly and internal stresses 
are set up. 

It would, from a reinforced concrete point of view, 
be advantageous to reserve such work for the cooler 
months of the year. This, however, cannot always well 
be arranged for, especially in the case of bridge work, 
which has to be pushed on when the rivers are not in 
flood and the season hottest. 

River Wall at Calabar. 

A reinforced concrete river wall is shown on 
Plate I, built at Calabar. The object of the wall was 
to retain a considerable area of low-lying marshy 
ground along the river front, and to serve as a wharf 
for boats. 

Owing to the soft nature of the soil it was decided 
that a mass concrete wall of suitable section would have 
been too heavy and costly for the purpose in view. 
An economical light reinforced wall of the design 
shown was, therefore, adopted, the total length of 
which was some 400 ft. 

Preliminary borings proved that at a depth of 20 ft., 
rails 75 lb. per ft. run weight could be driven to a firm, 
footing, and these were accordingly placed at 10 -ft. 
intervals, allowing the wall to be built in sections of 
that length. The wall was 12 in. thick and 10 ft. 
high, with a base of 5 ft. forming a toe towards the 
river. 

The whole of the foundation trench was carefully 
piled with timber, piling 2 ft. 6 in. apart, decked with 
2 -in. planking, and upon this the wall was built. 

Although it might be considered that the friction 
of the wall along this base is sufficient to prevent slip- 
ping, yet the tendency to slide was further safeguarded 



REINFORCED CONCRETE IN S. NIGERIA 399 

by the insertion of timber battens, 6 in. by 2 in. thick 
and 18 in. long, securely bolted to the decking in two 
rows, below the expanded metal and between the Khan 
bars (the system of reinforcement used), thus forming 
a key (fig. la). 

The reinforcement consisted of Khan bars cut into 
suitable lengths, placed 2 ft. 6 in. apart, laid hori- 
zontally along the base portion and vertically to a 
height of 7 ft. in the wall itself. 

Expanded metal of 3 in. mesh was then inserted 
along the entire length of both vertical and base por- 
tion of the wall, care being taken to fix the shear 
members of the bars through the meshes of the ex- 
panded metal so as to allow a true alignment. The 
sheets of expanded metal were joined together by 
wiring in the usual way. It will be observed that 
the wall has been strengthened at the corner and the 
expanded metal bent in a suitable manner. 

The depth of water at low tide was 2 ft., and by 
forming a dam of clay -puddle around each section as 
the tide receded, and pumping out the water ex- 
peditiously, the fixing of the reinforcement and placing 
of the concrete was successfully carried out. In this 
way the wall was built up to its height in 10-ft. sec- 
tions as the tides permitted. The concrete employed 
throughout was composed of 4 parts of river stone, 
1 in. gauge, and 2 parts of clean sand to 1 part of 
Portland cement. 

The ramming was done in layers of 4 in. thick, and 
was personally supervised by the writer ; 9 in. by 
3 in. timber sheet -piling was used at the back of the 
wall to form false work, as well as to keep the founda- 
tions clear of being fouled by soft soil. Timber 
shuttering of 2 in. thick planed boards was employed 
for the facework, and a clean, smooth surface was 
obtained. The exposed facework was treated with a 
cement wash of 3 : 1 to ensure a waterproof finish. 

The question of a suitable method of fixing the 
weepholes was a matter of careful consideration. 
Cement -pipes 12 in. long with 3 in. external and if in. 
internal dimensions were cast in sand and cement, 3:1, 
for insertion between the meshes of the expanded metal 
(Fig. 4), 5 ft. apart in two rows. 

The joists with the face and back of the wall were 



400 THE CONCRETE INSTITUTE 

grouted with cement mortar, thus the reinforcement 
was effectively protected against leakage of water and 
consequent oxidization. 

The light nature of this reinforced wall did not 
permit of any surcharge, and it was important that the 
filling behind be carried some distance back at the 
same level of the wall. It was also stipulated that no 
building should be erected beyond the point where it 
was considered that the limiting line of rupture would 
occur. 

The attention of the writer has been drawn to some 
criticism as to the stability of a wall of this type. 5 It 
was said that a reinforced wall being much lighter 
than that of a mass concrete wall of similar height 
and base, the resultant of pressure due to its weight 
and that of the earth behind it would be dangerously 
near the toe of the wall. The writer would point out, 
however, that as the centre of gravity of the reinforced 
wall is considerably nearer the inside of the figure 
than in the case of a mass concrete wall, consequently 
the line of pressure will be found to be consistent with 
safety. Plate I, Fig. 3, explains the position. 

Bridges . 

Several bridges of the type shown on Plate II. 
have been recently erected under the writer's super- 
vision. The particular one described was built over 
one of the Niger tributaries some 180 miles up the 
river. 

The bridge was originally planned in two spans of 
20 ft. each with cast-iron screw pile supports in the 
centre. It was subsequently decided, however, that 
the volume of water which would accumulate in the 
rainy season necessitated the addition of an extra span, 
and as no other piles were available at the time, the 
concrete pier was built. 

The stream spreads itself over very swampy ground 
on either bank, and clay-puddle dams had to be built 
before the foundation piles and abutments were put 
in. The screw piles were tested with a dead load of 
10 tons each until the settlement was observed to be 
/,; in., before the reinforced concrete girders were 

1 " The Engineer," August, 1909. 



REINFORCED CONCRETE IN S. NIGERIA 401 

cast over them. Each girder, 20 in. by 12 in. section, 
was reinforced longitudinally by | in. by \ in. iron 
bars placed in the manner shown in Figs. 3 and 4. 
Stirrups were provided at 3 ft. intervals, to which the 
bars were wired and reinforcement carried out as 
indicated. The centering was set to a camber 
of I in. to allow for settlement, and the false work 
framed (Fig. 6) in a manner which allowed the sides 
to be removed ten days after moulding, leaving the 
bottoms a fortnight later. 

The reinforced slab, 8 in. thick, which carries the 
roadway, was composed of \ in. by \ in. iron bars 
laid 8 in. apart, i| in. from the underside, and inter- 
laced with i in. galvanized wire 4 in. apart. The 
projecting portion was reinforced in a similar manner 
1^ in. from the upper surface (Fig. 4). 

The concrete in girders and slabs was composed 
of 3^ parts of stone broken to a f-in. gauge, and 
2-| parts of sand to 1 part of Portland cement. All 
the reinforced concrete work is as far as possible mono- 
lithic, which ensures the structure being very solid. 

Relative Advantages. 

It might be asked whether reinforced concrete is a 
material to be economically applied in West Africa. 
In such an undeveloped country as this the engineer 
is faced with the question whether the local conditions 
lend themselves to that degree of economy which justi- 
fies its adoption. The saving in cost of material, and 
the facility with which iron rods and packages of 
cement in sealed tins can be transported over long 
distances of rough country are very apparent against 
the expense of heavy ironwork and the difficulties 
of transport it involves. But, on the other hand, it 
has to be borne in mind that native labour has not 
attained a very high standard of perfection. The 
engineer (who is certain to have many works to attend 
to at considerable distances apart) might with fair 
assurance feel that his iron girders and troughs can 
come to little harm while their erection is proceeding 
by a native staff in his absence. But reinforced con- 
crete demands the constant personal supervision of a 
competent European foreman, and this supervision is 



4 02 THE CONXRETE INSTITUTE 

not always available at the moment the engineer would 
most need it, and it is a considerable item of expense 
when the question of cost of work is considered. The 
writer is of opinion that in West Africa, although the 
advantage in cost of material and transport is on the 
side of reinforced concrete, yet it behoves the engineer 
to look with special care into the question of super- 
vision before rushing into reinforced concrete work 
too hastily. 



TWENTY -SEVENTH ORDINARY GENERAL 
MEETING 

Thursday, November 14, 191 2 

THE TWENTY-SEVENTH ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296 Vauxhall 
Bridge Road, Victoria, S.W., on Thursday, Novem- 
ber 14, 1912, at 7.30 p.m., 

Mr. E. P. WELLS, J. P., the President, in the 
Chair. 

THE PRESIDENT :— The first business that we 
have this evening is the election of new Members to 
the Concrete Institute. I shall not put each one 
to you separately, but will read their names over and 
assume they have been approved, unless I hear to the 
contrary. 

1. Mr. Walter J. R. Barker, Architect and Sur- 
veyor, Licentiate R.I.B.A., H.M. Office of Works, 
16, Queen Anne's Gate, Westminster, S.W. 

2. Mr. George J. Bertins haw, General Manager, 
New Zealand Ferro-Concrete Structural Engineering 
Company, 92, Jorvois Quay, Wellington, N.Z. 

3. Mr. William E. A. Brown, A.R.I.B.A., 9, 
Regent Street, S.W. 

4. Mr. Robert Cathcart, Member of the Am. 
Soc. of Testg. Materials, Mem. Int. Assn. Testg. 
Materials, Mem. National Cement Users' Association, 
Madison Avenue, Cleveland, Ohio, U.S.A. 

5. Mr. Robert T. Cooke, Engineer, c/o British 
Reinforced Concrete Engineering Company, Ltd., 
82, Victoria Street, S.W. 

6. MR. J. D. CORMACK, Professor of Mechanical 



4 o 4 THE CONCRETE INSTITUTE 

Engineering, M.Inst.C.E., M.I.Mech.E., M.I.E.E.,. 
D.Sc. University College, London. 

7. Mr. J. Percy Day, Civil Engineer, Manager 
of the Euboeolith Patent Flooring Company, 3, Victoria 
Street, S.W. 

8. Mr. P. Ion Elton, A.R.I.B.A., P.A.S.I., 
Building Construction Surveyor, 113, Gloucester Road, 
South Kensington. 

9. Mr. John W. Gibson, Engineer, c/o Messrs. S. 
Pearson and Son, Ltd., Hull Joint Dock, Hull. 

10. Mr. A. W. Green, A.M.I.C.E. (Ireland), 
Manager, Samson Concrete Construction Company, 
Ltd., 71, 72, Broad Street Avenue. 

11. Mr. Charles M. Gregory, Contractor of 
large Rly. Engineering Works in India, 16, Bruns- 
wick Place, Hove, Brighton. 

12. Mr. Charles A. Duncan, Engineer, Public 
Works Dept., Behar and Orissa, India. 

13. Mr. James M. Jardine, Clerk of Works, H.M. 
Office of Works, Edinburgh. 

14. Mr. A. Bryce Johnstone, Engineer. Port 
Victoria, Espirito, Santos, Brazil. 

15. Mr. William Russell Kerr, Manager, Reid 
Bros, and Russell Proprietary, Ltd., 458-60, Flinders 
Street, Melbourne, Australia. 

16. Mr. W. H. Lascelles, Contractor, 66, Victoria 
Street, S.W. 

17. Mr. Walter J. H. Leyerton, Licentiate 
R.I.B.A., M. Arch. Association, H.M. Office of Works, 
22, Carlisle Place, S.W. 

18. Mr. S. G. Lyttle, Assoc. Soc. Arch., Stud. 
Inst.C.E., P.W. Dept., S.M. Railway, Bijapur, India. 

19. Mr. George Metson, M.R.San. I., Licentiate 
R.I.B.A., H.M. Office of Works, Church Street, 
Islington, N. 

20. Mr. A. Hedley Quick, A. M.Inst.C.E., 
A .M.I.Mech.E., A.M.Inst. Mun. and County En- 
gineers, Engineers' Dept., London County Council, 
Spring Gardens, S.W. 

21. MR. G. T. Ritchie, A.M.I.C.E., B.Sc. (Bir- 
mingham Civil Engineering), Irrigation Dept., Cape 
Town, Transvaal . 

22. Mr. G. M. Stonier, Messrs. Richard Johnson 
Clapham and Morris, Manchester. 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 405 

23. Mr. J. Edge Taylor, Designer in Reinforced 
Concrete, c/o Messrs. Trussed Concrete Steel Company, 
Ltd., Caxton House, S.W. 

24. Mr. Wilfrid W. Tonkin, Licentiate R.I.B.A., 
Registered Architect, Transvaal Assoc, of Architects, 
P.W. Dept., Johannesburg, Transvaal. 

25. Mr. F. J. Treacher, Manager, Steel Con- 
struction Company, Ltd., Malvern. 

26. Mr. H. A. Tristram, Proprietor of Andrew 
Hawksley Patent Tread and Engineering Company, 
Columbia Works, Prescott Street, Poplar, E. 

27. Mr. Hamilton H. Turner, M. Quantity Sur- 
veyors' Association, 11, Dartmouth Street, West- 
minster, S.W. 

28. Mr. Percy J. Waldram, Licentiate R.I.B.A., 
F.S.I., M. Arch. Assoc, M Jun. Inst. Engineers, etc., 12, 
Buckingham Street, Charing Cross. 

29. Mr. F. Vernon Wharton, Articled to Hon. 
A. G. Bell, P.W. Dept., Port of Spain, Trinidad. 

The greater number of the members whose names 
I have given are resident in England, and a few of 
them abroad. There have also been admitted by the 
Council as Students the following : — 

1. Mr. T. H. Alderton, Engineering Cadet, 
Public Works Dept., Auckland, N.Z. 

2. Mr. Philip Richard Dunkley, Draughtsman, 
Trussed Concrete Steel Company, Ltd., Caxton House. 
Westminster, S.W. 

3. Mr. Harry Vincent Whittaker, Draughts- 
man, 125, Minories, E. 

This, gentlemen, brings the number of members 
up to date to 899, students, 32, special subscribers, 7, 
giving a total of 938, so that we are getting very close 
to the thousand, which I hope we will attain very 
shortly. (Cheers.) 

THE PRESIDENT (Mr. E. Wells, J. P.), then 
read his Address as follows : — 

PRESIDENTIAL ADDRESS. 

It affords me very much pleasure, in addressing you 
for the first time as President of the Concrete Institute, 
to congratulate you upon the various subjects that 



4o6 THE CONCRETE INSTITUTE 

have been taken up by the Committees during the 
past year, and also upon the satisfactory state of the 
Institute's membership, which, I am pleased to see, 
is gradually increasing, and it is the hope of the 
Council that before another two or three years are 
passed the membership will be doubled. 

The Committees of the Institute have a great many 
subjects at the present time under consideration. The 
Science Committee, it will be recollected, drafted a 
Standard Notation for Calculations for Reinforced Con- 
crete, which was subsequently adopted by the Joint 
Committee on Reinforced Concrete appointed by the 
Royal Institute of British Architects in their Second 
Report, and by the London County Council in their 
proposed Regulations covering the erection of buildings 
in reinforced concrete in London, while text-books 
which have been published in London since that date 
have also followed its recommendations. This, I think, 
will be felt as a great feather in the cap of this Institute. 

You are all aware that the scope of the Institute 
has been enlarged — and not before it was wanted — 
to include structural engineering. The Science Com- 
mittee has undertaken to compile a Standard Notation 
for Calculations in Structural Engineering generally. 
Further effort in the direction of standardisation is 
being made by the same Committee in drafting a 
standard specification for reinforced concrete work, 
which, at the present time, is very badly needed, and 
also a Report on the standardisation of attachments 
or joints in reinforced concrete. Other subjects of 
some importance are under investigation — viz., rein- 
forced concrete piles, chemical tests for steel used in 
reinforced concrete, the adhesion of or friction between 
the concrete and the steel, and the effect of sewage, 
oils, and fats on concrete. In respect to the last 
named, it will have been seen that papers are to be 
given this Session on the same subject. These papers 
will be duly considered by the Committee in drafting 
their Report, and it will be in the recollection of many 
of you that a paper by Mr. Sydney H. Chambers was 
given in the 1910-11 Session on "The Effects of 
Sewage and Sewage Gases on Portland Cement Con- 
crete," which, you may remember, was also very fully 
discussed at the time ; the full Report of the Meeting 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 407 

is to be found in the Proceedings of that year. This 
Report will also be taken into due account by the 
Committee. 

Other Committees of this Institute have also been 
very hard at work on other branches of the subject 
on which standardisation may be advantageously 
brought to bear ; and with regard to this, the Institute 
conducts a Joint Committee on Loads on Highway 
Bridges, upon which the Institution of Municipal and 
County Engineers and the Institution of Municipal 
Engineers have representatives. The Joint Committee 
is now engaged in drafting a Report, and no doubt 
when their work is finished it will prove of distinct 
service, not only to the Government but to the muni- 
cipal authorities throughout the country. 

The Tests Standing Committee have the following 
subjects under consideration, and you will note from 
the number of the subjects that a great amount of work 
will be entailed upon this Committee in gathering the 
information which in time will be presented to the 
members : — 

1 . The effect upon steel of the presence of sulphur 

in aggregates. 

2. The grading of aggregates. 

3. The expansion and deterioration of concrete 

due to changes of atmospheric temperature. 

4. The effect of the use of sodium silicate on the 

surface of concrete as affecting reinforcing 
metal. 

5 . The erratic results obtained by the Vicat needle 

in ascertaining the initial set of cement. 

The Reinforced Concrete Practice Standing Com- 
mittee are investigating : — 

1 . Methods of treating the surface of concrete . 

2. Cracks due to the expansion and contraction 

' of reinforced concrete. 

A special Investigation Sub -Committee has been 
formed to investigate failures and accidents in con- 
nection with reinforced concrete construction, and also 
the restrictions placed by the Local Government Board 
upon the granting of loans to local authorities for the 
purpose of undertaking work in that material. 



4 o8 THE CONCRETE INSTITUTE 

The Committee which was appointed to consider the 
widened scope of the Concrete Institute, and whose 
Report in favour of the course of including within its 
purview the whole field of structural engineering 
was adopted by the Council, has not been wound up, 
but will continue to meet as an Improvements Com- 
mittee. 

1 may as well state here that the Committees will 
be very pleased indeed to receive any matter of im- 
portance bearing on these subjects that any member 
may like to write to them, and I take this opportunity 
of saying that if any of you at the present time have 
anything in your minds bearing upon these matters 
to be dealt with, will you kindly communicate with 
the Secretary, and it will be laid before the Committees 
at their next Meetings. 

It will be seen from the programme for next Session 
that the widening policy is already taking shape by 
the inclusion oJ a few papers on subjects not having 
immediate connection with concrete. The result has 
been that a greater number of General Meetings will 
be held this Session than last, and it is thought that 
a more interesting programme will be furnished. It 
may be mentioned that last Session only nine General 
Meetings were held, whereas for this year thirteen 
General Meetings and six Educational Lectures have 
been arranged. I may say the first one of the educa- 
tional lectures started this week, and it was extremely 
well attended, I believe over 125 being present. It 
was decided, on the recommendation of the Im- 
provements Committee, to have such a course of 
educational lectures annually, and also to hold an 
examination in structural engineering once a year 
to test the scientific or technical attainments of 
applicants for Studentship. The first examination will 
in all probability be held next year, and is in the right 
direction as regards increasing the status of members 
of the Institute because the qualifications for member- 
ship have been tightened up, and in due time it is 
probable an examination will be held for the admission 
of members, although it is hoped it will never be 
insisted upon a absolutely necessary to admit an 
engineer to men jrship, because there have been and 
no doubt will be engineers who for various reasons 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 409 

will not or cannot submit themselves for examination, 
yet who are well qualified and would be worthy 
members of the Institute. At thp present time the 
Institute is open to persons who are connected with 
the manufacture or commercial development of 
materials and methods of construction included in the 
field of structural engineering. Such members are 
of much value to the Institute, and I feel sure it 
would not be the wish of any one who has the interest 
of the Institute at heart to exclude such persons, 
although, if the policy of developing the structural 
engineering side is continued, it may be necessary to 
give such persons a special classification. 

The Concrete Institute has now on the recommenda- 
tion of its Committee the sub-title reading " An 
Institution for Structural Engineers, Architects, etc." 
The word " Architects " is included because they have 
to design structures from the engineering standpoint ; 
but also they have to study the artistic tside of con- 
struction, or the aesthetic treatment of structural 
materials. That is an aspect which the Concrete Institute 
has kept in mind and which it is desirable should 
continue to receive consideration ; but I think it 
would be as well if the words " Institution of Structural 
Engineers " were added permanently to the main title 
of the Institute, though this is a matter that will 
probably come up later on. There are great possi- 
bilities in such a development, as there are evidently 
fine opportunities for such an Institution, and, 
considering that all the users of concrete must 
necessarily be connected with the theory and design 
of structures in some form or another, it is only a 
natural course to pursue on our part. 

The work of the Institute is now growing very 
rapidly, and compared with what is being done by 
other institutions, the subscription is very small indeed. 
The Council, I think, have wisely adopted the decision 
to require an entrance fee when the membership 
reaches one thousand, which it is hoped will very 
soon be the case. 

At the present time the Council have an insuffi- 
ciency of funds to enable them to proceed in the 
direction of experimenting upon the s ,ject of rein- 
forced concrete, and until some method is adopted of 



4io THE CONCRETE INSTITUTE 

increasing the revenue this question of experimenting 
will have to be deferred. Mr. C. S. Meik informed me 
before the Meeting that the Institution of Civil 
Engineers have all the necessary plant for the testing 
of reinforced concrete slabs, and I think from what 
he said that they would be prepared to let anybody 
make the tests on the understanding that all data 
is communicated to the Institution and that it is done 
under their supervision. The only way that it seems 
possible to obtain the necessary funds will be to 
increase the subscription of the home members, but 
with regard to foreign members they might remain 
the same as at present. If this were done and the 
revenue doubled without any large increase of estab- 
lishment charges, then the Council would be able to 
undertake experiments which would be for the good 
of all those interested in concrete and structural 
engineering. 

I propose in this, my first Presidential Address, to 
deal almost wholly with the practical side of reinforced 
concrete construction, as I consider that the more often 
attention is called to this most important part of the 
work the better it is for all concerned, both for the 
engineer, the architect, the proprietor, and also the 
contractor. 

With regard to the first and the principal constituent 
in concrete — namely, Portland cement — it is strange, 
at this present day, how many engineers and 
architects still adhere to the old specification of 
coarse grinding, consequently requiring aeration of 
the cement. It has been my lot only this week to 
come across a specification where it was stated the 
cement had to be spread on a floor for twenty -one 
days before being used. Those of us who are well 
acquainted with the present-day cement, and also its 
fine grinding, know how deleterious this is when great 
crushing strength is required. I think I have said, on 
more than one occasion at this Institute, that if cement 
is to be kept up to its full strength it is absolutely 
necessary that when it is received on the site of the 
works it should be stored in air-tight wooden bins : 
and if this is done cement may be kept for many 
years and be just as good after the lapse of time as 
it was when freshly made, whereas if the cement be 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 411 

stored in sacks, and even a very small amount of moist 
air plays upon them, then the cement is rapidly 
hydrated and cakes in the sack. If, as is often the 
case, this cement be rubbed through a sieve, it becomes, 
almost absolutely useless for purposes of concrete- 
making — by that I mean good concrete. 

I have in my mind's eye a case of a contractor who 
bought cement in the month of October. The whole 
winter was a bad one, and he had very little oppor- 
tunity of using the cement. It was stored in a shed 
through which the wind could blow freely, and he 
was rather astonished when the spring came and the 
cement was used that it would not set. He then wrote 
to the manufacturers, and when the matter was investi- 
gated the true cause of the mischief was iound out. 

I have myself on many occasions experimented with 
cement that has been so hydrated, and it is astonishing 
the enormous reduction in the strength, so much so 
that it becomes almost useless for making concrete. 

Any of you who chooses to make the experiment can 
do so, and you will find that with the concrete made 
from an over-hydrated cement the amount of strength 
obtained will be very little indeed, and that its setting 
action will be so slow that it will practically take days 
before it shows much sign of hardening. The only 
use of such a cement is to mix with an over -clayed 
cement that is too quick setting ; by this means the 
setting action can be retarded. 

Passing from cement, one is led on to the careful 
choice in all aggregates, the proper grading of the 
same, and also, what is of more importance, the seeing 
that everything is absolutely clean and the water pure. 

I know it has been said that dirt is of some good in 
increasing the strength of cement concrete, but the 
only case that I can find where, over any period, a 
dirty aggregate increased the strength of the concrete 
was due to the fact that it had been mixed with a 
very over-clayed cement. It slowed down its setting 
action, and by that means did good ; but if the test 
had been carried over a lengthy period, it would have 
been proved how fallacious is the advantage to concrete 
of dirt in any form. 

With regard to aggregates consisting of gravels 
that are dredged either from the river or from the 



4 i2 THE CONCRETE INSTITUTE 

bed of the ocean, it is very seldom that the proper 
proportion of sand to coarse material is obtained. 
There is only one gravel that I know where one can 
see that the proportion is about correct, and that is 
obtained from the Spurn. In the ballast obtained 
from the Thames and along the East Coast there is at 
the present time a great excess of sand, and under 
any circumstances I would not in any way recommend 
that this aggregate should be used without separation 
of the larger particles from the finer and subsequent 
crushing of the coarse material. 

The difference in the strength of concrete made with 
an excess of sand is very marked where the propor- 
tion of cement is not great ; that is to say, 6 to I and 
7 to i concretes with an excess of sand show very great 
falling off in strength, whereas with richer mixtures 
and an excess of sand, though there is a falling off in 
the early stages of hardening, after a few years the 
concrete will almost come up in strength to a concrete 
made in the correct proportions. Of course, it is well 
known that for all waterwork a large proportion of sand 
is required so as to get a perfectly dense mixture, but 
in no case must this be overdone. 

In concrete for waterwork it is not necessary to add 
anything to make it watertight. If concrete be properly 
made it will be absolutely impervious to moisture, 
and if it be found necessary to reduce the labour some 
of these compounds of hydrated lime are, no doubt, 
of utility in decreasing porosity, but, at the same time, 
concrete so made is not improved in strength. 

Before leaving the subject of aggregates I wish to 
call particular attention, as I have done here on more 
than one occasion, to the use of Fletton bricks for 
concrete. I have found lately that wherever Fletton 
bricks have been used disruption has taken place in 
the concrete, and I think this is due to the presence 
of lime in the bricks. Fletton bricks that are 
dangerous to use are those with purple markings, 
and great care should be exercised by all those who 
propose to use brick aggregate for concrete work 
to eliminate absolutely Fletton bricks in any form 
whatever. In this I am borne out by several who 
have been unfortunate enough to use the bricks, the 
result being that the concrete has failed. 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 413 

I was called in only a few months ago to a special 
floor that had been put down for testing bowls, when 
it was found that about a month after the floor had 
been laid it was becoming uneven in places. On 
examination it was found that in every case where the 
floor had risen Fletton bricks in the aggregate were 
the cause of the mischief. 

It is always advisable in the making of concrete 
that it should be got into the work as quickly as 
possible, especially in the summer : with low tempera- 
tures it is not of such great importance, as the cold 
slows the setting action and also its hardening. In 
frosty weather the drier the concrete and the more 
ramming, so long as there is no chance of displacing 
any of the reinforcing, the better for the concrete, as 
it will set very much more rapidly than if there is 
an excess of moisture. 

With regard to reinforced work it is far better that 
the concrete should have a slight excess of moisture 
than a deficiency. Certain experiences that I have 
had lately have shown that where steel has been put 
into concrete that was too dry, the air and moisture 
had got through the porous concrete to the steel and 
caused rapid corrosion. 

In one case the bottom layer of concrete had been 
put in and allowed to set, the steel was placed on the 
dry concrete, and other dry concrete was placed on 
top. When this work was broken up it was found 
that the rods in the concrete were quite loose, could 
be turned round by hand, and the adhesion between 
the two layers of concrete was anything but good. 
Now, had the concrete been made wet, there would 
have been no separation between the steel and the 
concrete, it would not have been possible to twist 
the steel rods round in the concrete, neither would 
moisture have passed through the concrete to the 
steel and caused oxydisation after the alkaline salts 
had disappeared by age owing to the presence of air 
and moisture. 

Excess of moisture, as we all know, decreases the 
crushing strength of the concrete ; but at the same 
time in nearly all structures there is generally such 
an excess of concrete in the compression member, 
especially where T-headed beams are used, that it 

EE 



414 THE CONCRETE INSTITUTE 

is better to have the steal perfectly protected with 
a slightly weaker concrete than to have imperfect 
protection with a stronger concrete, because if 
imperfectly protected corrosion will be almost bound 
to take place, with consequent disruption of the 
concrete. 

Excessive ramming in concrete is not at all 
necessary where it is made wet. It is far better to 
employ very light ramming and see that fine particles 
of the concrete are brought to the surface of the 
shuttering boards by means of steel slices or trowels. 
If this be done there will be very little danger of 
air finding its way through into the steel reinforcing, 
but a coarse aggregate first put in with an insufficiency 
of sand is almost always certain to have some porous 
parts through which the air and sulphur, especially 
in a London atmosphere, can attack the steel . 

It may be well here to call attention to what I 
consider to be a most important point in reinforced 
concrete construction, namely, that as the concrete is 
being put into the work test -cubes should be made 
both for ascertaining the strength of the concrete in 
situ and exposed to the ordinary atmospheric con- 
ditions, and also to ascertain in the laboratory the 
strength of a series of cubes made at the same time 
and kept under laboratory conditions. One set of cubes 
should be kept on the works exposed to the varying 
atmospheric conditions, and the other at the laboratory 
at the normal temperature, say, of 6o° Fahr. 

Some years ago I made an experiment to see 
whether cold had any effect on concrete, and if so, to 
what extent. I found that in the month of December, 
when the cubes were taken from about 6o° Fahr . 
and placed on a roof where the temperature fell to 
below freezing-point, a most alarming decrease took 
place in the crushing resistance of the concrete, and 
this remained so until such time as the weather became 
warmer, when the crushing resistance went up and was 
practically the same as shown by cubes made to the 
same gauging but kept under normal conditions. 

This clearly shows that if a building is constructed 
in cold weather the crushing resistance of the concrete 
cubes kept on the works will be low, but if it be found 
that the other set of test -cubes, kept under laboratory 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 415 

conditions, shows a rapid increase in the strength, 
then it is only fair to assume that the concrete that 
has been exposed to the cold air will, with favourable 
conditions, increase in strength and attain the same 
strength as the laboratory experiments. 

The reason I am calling particular attention to this 
point is that if a building is constructed in the winter 
and the test loads are applied up to 50 per cent, in 
excess while the weather is cold, there may possibly 
be an excessive amount of deflection, owing to the 
fact that the strength of the concrete in compression 
is low, whereas if the experiment were held over 
until the warmer weather, when the compressive 
strength of the concrete was largely increased, then 
the deflection would be practically nothing — of course, 
assuming that the work in the first instance had been 
properly designed. 

If the work is properly designed, and if the super- 
vision has been strict and the work has been carried 
out according to the drawings, it is fair entirely to 
dispense with the testing of the structure so long 
as the experimental cubes show that the concrete 
has attained the strength required by the engineer 
or architect. 

It is rather foolish to test a structure when one 
knows by experience that the crushing resistance, owing 
to the cold, is low. It would be far better to wait until 
the weather had become warmer and the concrete had 
parted with a lot of its moisture, when it would have 
become much harder. On the contrary, if it is found 
that the laboratory tests are low, say, for the sake of 
example, one month after being made, then I should 
strongly recommend testing of the structure to ascer- 
tain whether there were anything seriously at fault. 
Having those conditions of a low laboratory test and a 
much lower in situ test, yet the structure not exhibiting 
any serious deflection, then the work may be passed ; 
but still, it is advisable in all cases to watch the crush- 
ing experiments, as upon these depends almost entirely 
the strength of the structure. A good crushing 
resistance means that the concrete is strong in tension, 
strong in adhesion, and strong in shear, and such 
being so, there is very little danger of the structure 
failing even if there is a deficiency of steel. 



416 THE CONCRETE INSTITUTE 

The testing of floors and other works is, as a rule,, 
carried out on much too small a scale. Testing 
should be spread over an area that will at least take 
in always two sets of secondary beams as well as 
two spans of main beams completely. By this method 
of testing, the beams always have their full load and 
the adjoining beams become unloaded, which gives 
the most severe form of test, unless absolute con- 
tinuous construction be carried out. 

My experience has taught me that where concrete 
is good, that is to say, mixtures of 5 to 1 and richer, 
with the ordinary normal loading for which the struc- 
ture was designed, unless most delicate instruments 
be used there will be no deflection recorded, whereas 
when weak concretes are used, namely, 6 to 1 and 
under, then the deflection at times becomes very great. 

In all cases in making deflection tests, they should 
be made, not only at the centre of the span but also 
at the walls, as very often it is found that a large 
amount of the so-called deflection is due entirely to 
the squeezing of the brickwork, owing to the fact 
that the reaction has not been spread over a sufficient 
area of brickwork. In no case ought the load on 
the brickwork to exceed eight tons per square foot ; 
by this means a good distribution is obtained and 
the brick walls are strengthened thereby. 

In a great many works that I have seen where 
failures have taken place, the failures have been very 
largely attributable to shuttering and strutting. I have 
in mind cases of beams deflecting two or three inches 
after the concrete has been filled into the mould, this 
being due entirely to the strutting sinking into the 
soft ground underneath. In several cases this has 
caused what appeared like shear cracks at each abut- 
ment, though the work afterwards stood the test load 
satisfactorily. Still, such cracks made the beam look 
unsightly, and there could not have been the same 
adhesion between the concrete and steel, owing to 
this settlement, as if the boxes had remained perfectly 
true and level during the whole time the concrete was 
being put in and until the same were struck. 

I know of one case of a failure taking place entirely 
owing to the strutting sinking into the ground, the 
sinking taking place over more than a week. The 



TWENTY-SEVENTH MEETING, Nov. 14, 191 2 417 

concrete, therefore, never had the least chance of 
getting a fair adhesion to the steel, but was constantly 
being drawn away from it by this settlement of the 
strutting, so much so that when the strutting was 
removed the whole structure came down with a run. 

It is always advisable, if there is any doubt at all 
about the ground, to have the latter tested beforehand, 
and it is far better to increase the sole-plates to 
double the size required, so as to prevent any possible 
chance of settlement, than to have an insufficient 
area with consequent settlement and trouble taking 1 
place. 

Not only does the settlement cause a reverse camber 
of the beam, but it also gives a fall in the floors the 
wrong way, and it needs extra expense all round to 
make good such defective work. 

All these are points that are easily obviated by the 
simple means of closely watching the work as it pro- 
ceeds, and not allowing any concrete to be put in until 
the engineer or his representative is satisfied that the 
strutting is of such a nature that settlement is not likely 
to take place. 

Strutting should always remain up as long as 
possible after the concrete has been placed in position ; 
in fact, if it were not for the exigencies of trade 
and also the rapidity with which building works of the 
present day have to be erected, I should personally 
like to see all strutting remain up for very much 
longer periods than is generally allowed, because the 
harder concrete can get before removal and any weight 
can get thrown upon it the better it is for the structure 
as a whole. Unfortunately, in the present day the 
question of expense has to be very largely considered, 
and to allow strutting to remain up as long as one 
would like it would increase in a great many cases the 
cost of the work, and I am afraid it would become 
almost prohibitive. Of course, in cold weather 
strutting must be left up for periods 50 per cent, longer 
than is allowed in the summer-time, and a great many 
of the failures in this country, and more especially in 
America, are mainly traceable to the removal of the 
shuttering and strutting at too early a period in 
the life of the concrete. The concrete at the time 
of striking was weak, but had an extra fortnight or 



4 i8 THE CONCRETE INSTITUTE 

more been allowed for the hardening, then the works 
that have failed would no doubt have stood up. 

Before finishing with concrete-making I would like 
to refer to water to be used therein. In this country, 
as a rule, water is almost invariably obtained from what 
is called a domestic source, namely, water supplied 
by large public companies who are extremely careful 
in what is sold to the public. Such being so, it 
is very rarely in England that one has to use water that 
does not come from the public supply ; but there 
are cases where it is advisable carefully to examine 
the same before it is used. There are some places 
where the water is highly charged with gypsum com- 
pounds, and such being the case, it behoves one to 
see that there is no likelihood of failure taking place 
owing to an excess of this compound. 

In the South of France, in Algeria, and in a great 
many districts waters are highly charged with gypsum, 
and so bad is this in places that concrete is absolutely 
dissolved and disrupted in less than two or three 
years. Whenever there is any doubt as to the quality 
of the water to be employed an analysis should be 
made beforehand, and so what might lead to a disaster 
guarded against. 

One of the great defects with regard to reinforced 
concrete is constantly raised by those who have not 
had much to do with the subject and often by those 
who are largely connected with it, namely, the difficulty 
of getting steelwork placed in the position designed 
by the engineer. It is a difficult matter always to 
get the work placed in the designed position, owing 
to the carelessness of the British workman, whose 
idea seems to be to get the material into position 
as quickly as possible, no matter whether it be right 
or wrong, and in a great many cases if he has an 
opportunity of leaving the steel out he will do so. 
The only way to get over this difficulty is not to allow 
any concrete to be filled or poured in until the steel- 
work had been passed by the engineer or his repre- 
sentative. If this be done there will be very little 
danger to be apprehended, because if the steel is in 
the correct position, if the concrete is proved to be 
as good as borne out by the in situ tests and by 
the laboratory tests, and if the strutting has not given 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 419 

way, then one may fairly assume that the work has 
been well carried out and will sustain all the loads 
for which it is designed, and that there will be no 
deflection, or else of such a slight nature that it is not 
worth troubling about. If, however, the steel be 
badly placed, the concrete be poor, and the strutting 
has failed, then there is no knowing what is going 
to be the result. 

In a great many years of practical experience I 
have come to this conclusion, that even if there is 
a large deficiency of steel in the structure both in 
tension and in compression, and the concrete is of 
an excellent quality, there is hardly any chance of 
failure taking place, but if the steel is up to and even in 
excess of the requirements asked for, and by any chance 
the concrete be poor, then if an excessive load be 
placed upon the structure, there is nothing to prevent 
it failing. As I have stated before, a rich concrete 
is strong in crushing, tension, adhesion, and shear, 
whereas with poor concrete exactly the reverse is the 
case. 

A series of experiments that I carried out some 
years ago of some beams gave for thirty -three days' test 
a factor of safety of 5^ to 1 ; in three years the factor 
was over 9 to 1 . The whole of this was due entirely to 
a very good concrete which was absolutely homo- 
geneous throughout, and when the beams broke they 
failed only at the centre, the only place where cracks 
developed. There was no sign of shear, and the 
diameters of the rods where the failure took place were, 
to all intents and purposes, the same diameters as 
when they were put in. These experiments, I think, 
simply show an enormous increase in the lever -arm, 
due to the rich concrete ; in fact, in the case I now 
mention the lever -arm was practically the total depth 
from the axis of the tension members to the outside 
of the compression member of the beam ; but even 
this will not account wholly for the enormous load 
that the beams carried, as the tests produced 
extraordinary stresses both in the steel and also in the 
concrete itself. 

A great deal has been done by the London County 
Council School of Building in educating clerks of the 
works and others as to the method in which the prac- 



4 2o THE CONCRETE INSTITUTE 

tical part of reinforced concrete construction should 
be carried out. They ought to go a step lower and 
take in hand labourers who are connected with the 
carrying out of the work, because until such time 
as they themselves understand, to even a very slight 
extent, what is required of them, so long will they be 
careless in doing the work they have to do. 

The foremen employed must be instructed to keep 
a sharp look-out on all their men, and not to allow 
laxity in any shape or form. If the men know that the 
foreman is up to all their so-called tricks of the trade, 
then they will take good care that the work is 
carried out in an efficient manner, but if by any 
chance the foreman is careless his workmen will be 
the same ; and it will, I think, very often be found 
that where anything serious takes place it is not only 
the men but the foremen and even the clerk of the 
works on the job who are answerable for this state of 
affairs. 

Any foreman who persistently makes mistakes in the 
carrying out of the work, after the same have been 
pointed out to him, should be dismissed and not 
allowed to undertake any work of the kind in the 
future. It is only by making examples of men who 
do bad work that one can expect an improvement to 
take place in the industry in this country. Works 
executed abroad, as a rule, are carried out by men who 
seem to take a great interest in their work. Even the 
ordinary labourer knows what he has to do and does 
it, whereas in this country there are so many instances 
of scamping, not only in reinforced work but also 
in other branches of structural engineering, that it 
is only strict supervision in the past that practically 
made our work some of the best in the world, though 
I have very clear remembrances before me of seeing 
wooden rivets being used and other such things being 
done, and I daresay there are many in this room who 
have seen likewise. We do not hear of wood being 
put in for steel in reinforced concrete, that is to say, by 
the designer, but many accidents have proved that 
wood has been put in and has been the cause of the 
mischief. 

A point that was investigated by the Science Com- 
mittee some time ago was one which it is advisable, 



TWENTY-SEVENTH MEETING, Nov. 14 1912 421 

I think, for me to call attention to, and that is, electro- 
lysis. I have watched one work where this mischief 
occurred, and only about a couple of months ago I 
made a further examination and found that the mischief 
was still increasing. It is a moot point with some as 
to whether there is any electrolytic action or not ; but 
personally I have very little doubt upon the subject, so 
that it behoves all designers and contractors to see 
that there is no possible chance of electric currents find- 
ing their way into the steel reinforcement, because, 
should they do so, I do not think there is any doubt 
whatever that it will mean the eventual disruption of 
the concrete. It only requires the exercise of care to 
put a stop to this and to be perfectly certain that all 
cables throughout the reinforced concrete work are 
properly insulated, and that there are no stray currents 
wandering about the work. 

I think a great many of my hearers will agree with 
me in regard to the calculations of reinforced concrete 
work that a great deal too much mathematics has been 
imported into the subject and that common sense has 
had to take a back seat. 

If we were dealing with two materials, both of which 
were absolutely constant — that is to say, the concrete 
constant within a month after it was made in strength 
as the steel is immediately after it is rolled — then it 
would be possible to go in for mathematical formulae of 
a high order ; but where you have a material — i.e., 
concrete — the strength of which, if all portions are good, 
is increasing day by day, and in some cases attaining 
a strength of three, four, or more times that which it 
was originally calculated for, how is it possible in 
these ways to formulate any formulae which are even 
moderately correct ? It is far better to use more 
common sense and simplify or formulate empirical 
rules which you know are absolutely safe in their 
application. It is no good trying to extract the square 
root of two — it is useless. I have seen cases where 
the stresses have been worked out to five places of 
decimals, and it could all have been done by mental 
arithmetic, and the result would have been so close 
that it was really not worth while troubling about. 

I see cases constantly where rods are put into 
work varied in diameter to 32nds of an inch. 



422 THE CONXRETE INSTITUTE 

That is not at all necessary. It wastes time on the 
work, and in a great many cases a wrong rod goes 
into the wrong place. It is far better to adhere 
in all cases to commercial sizes, never advancing 
beyond i6ths of an inch and if possible advanc- 
ing only by iths, as by that means the size 
on the rod is clear to the naked eye and does not 
require a caliper to be put upon it to find out whether 
it is |5 or §| of an inch. Such reinforcements as these 
simply show how designers lack common sense and 
bring the work into disrepute. Exactly the same thing 
takes places with calculations submitted for approval. 
A mass of figures will be carried out into millions 
where the whole lot can ht simplified by reduction 
into tens or hundreds, and the elimination of anything 
beyond two places of decimals. The simpler calcula- 
tions are made, the less liability there is of errors 
creeping in, and if an error does creep in, then, it is 
much easier to discover ; but where a whole foolscap 
page of figures is used to arrive at a result, it means 
in a great many cases simply courting disaster, as 
well as being also a waste of time and expense with 
a view to p t ossibly saving a pennyworth of steel. 

I have always been a great enemy to the complicated 
calculations, as I do not think they are at all necessary. 
It only brings to mind the largest building that has 
ever been constructed in London. I am now speaking 
of as long ago as about five -and -twenty years. In an 
arch rib there was a deficiency in the centre of the 
span of, I think, half an inch in a large sectional 
area of steel. To make up this deficiency in com- 
pression a bar 2 in. by \ in. was riveted on, and 
this only for a length of two or three feet, thus 
making mathematics simply an absurdity, whereas no 
common-sense engineer would for the sake of half an 
inch in one hundred square inches ever think of doing 
anything so absurd. 

The same applies to reinforced concrete. It is far 
better to work in all cases to commercial sizes of rods, 
even if there be a slight deficiency in sectional area, 
than to put in multiples of rods of all diameter so 
as to make up a given sectional area. This entails 
an enormous amount of work, not only upon the 
designer but also upon the foreman who has to take 



TWENTY-SEVENTH MEETING, Nov. 14, 19 12 423 

charge of the work, and upon everybody connected 
therewith, and it is of no practical value whatever. 
Therefore I should like to see in all rules made for 
reinforced concrete that common sense should enter 
more largely into the formulas that are given to the 
world, and not a mass of mathematics provided, which 
the authors know perfectly well are even then 
empirical, because one material is a constant and the 
other is an inconstant. 

The Committees of the Concrete Institute have been 
seriously considering for a long time past the ques- 
tion of failures, and there is no doubt that if 
one could get at the whole facts of the cases with 
regard to failures they would be most instructive. 
As a rule, every work that fails has been kept in the 
background, for fear that the contractor or somebody 
in connection therewith would suffer either from the 
commercial point of view or the professional. It 
will be found, I think, as a rule, that the causes of 
failure are ones that can easily be allocated with the 
exercise of a little common sense and supervision. 
It is, as a rule, due to great carelessness on the part of 
foremen and workmen employed that the failures take 
place. Therefore it is advisable in all cases that the 
principal causes of failures should be known, in order 
that specifications may be made so rigid that there is 
little likelihood of these mishaps. It is the fear of 
failure that debars to a certain extent reinforced con- 
crete from being used by many clients, and therefore 
it should be the object of all concerned with this 
matter, from a professional as well as from a commer- 
cial standpoint, to see that such care be exercised in the 
whole of the work, both as to designing, checking, 
and construction, that no one, for one single instant, 
should have any doubt but that reinforced concrete is 
for certain classes of work the best that can be 
employed. 

It is no good, for instance, if a failure takes place 
where it can be fairly traced to a bad aggregate to 
keep the same a secret, because it means that others 
possibly in the same neighbourhood go on construct- 
ing work therewith and with the possible chance that 
failure will also occur, whereas had the fact of the 
failure been generally known there is not much likeli- 



424 THE CONCRETE INSTITUTE 

hood that a second disaster in the same locality would 
occur from the same cause. So that I make a con- 
fident appeal to all here to-night, and to all who may 
read the address, that wherever a failure in reinforced 
concrete takes place they will at once communicate 
with the Concrete Institute and let them have the 
facts of the case, not necessarily for publication but 
to enable the Institute to so word their suggested 
specification as to guard against a possible accident 
taking place in the future. 

It is only by failure that we are enlightened. All 
through life it is the same way, and we only learn and 
remember our alphabet at school by making mistakes 
and being punished for such mistakes so that we 
understand. So it is in a minor degree with the 
subject I am speaking to you about to-night ; the 
elucidation of a failure may be the means in the long 
run of saving an enormous amount of money. 

I think I have trespassed on your time more than 
I intended, but I trust that the matter of this Address 
is one that we all have at heart ; and if it is the 
means of causing work generally throughout the 
country to be carried out in a better manner than a 
lot has been done in the past, then it will be of some 
avail . 

MR. H. PERCY BOULNOIS, M.Inst.C.E., Chair- 
man of Council Royal Sanitary Institute, Vice- 
President Concrete Institute : — Gentlemen. I feel it a 
very great honour that I have been asked to propose 
a vote of thanks to our President for his address this 
evening. I have listened to that address with a great 
deal of pleasure, because I have been a President 
.myself of a good number of associations, and when 
one approaches the question of one's address one is 
met by the initial difficulty of what can one talk 
about. 

Now, I call the President's address a model one, 
because he has spoken to us of the subjects with 
which we have to deal. He has spoken to us of 
matters with which this great Institute is chiefly con- 
cerned. I think his epitome of the work that this 
Institute has done, and of the work that we hope to 
do in the future, is excellent. I must confess myself 
I am a little appalled when I see the work that is 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 425 

before us as a member of the Council, and there is 
no doubt that this Institute is doing an enormous 
amount of good. I believe that this Institute has 
not only come to stay, but that, in a very short time, 
it will be a marked power in this country for 
engineering purposes. 

The President has given us his address principally 
on what he calls the practical side of reinforced con- 
crete construction, and I think you will all agree 
with me that he has thoroughly met that title. Unfor- 
tunately, the President's address cannot be criticized, 
or cannot be discussed, because there is enough 
material in his paper to keep us here for a week. He 
has given us so many heads and various points that 
each one of those, I think, would make a paper in 
itself which would be well worthy of discussion. 

Take Portland cement, for instance ; he gives us 
a great many valuable hints with regard to Portland 
cement. I am old enough to remember when Port- 
land cement was practically first used in this country, 
and when Mr. Grant, who was then one of the district 
engineers of the Metropolitan Board of Works, read 
a paper at the Institution of Civil Engineers which 
caused a great stir. I belong to one of the old school 
who still think it necessary to weather cement, and I am 
not alone in that. We are told by the President that 
we do more harm than good by weathering it, and 
that the present method of making cement, the grind- 
ing and the hydrating, and so on, that go on makes 
a cement that can be used immediately it comes from 
the kiln. In the old days we called it hot cement, 
which had to be cooled or aerated. 

Then he deals with aggregates, a most interesting 
subject on which, of course, one could speak for a 
very long time. Then with regard to excess of 
moisture, it is perfectly true what he says, and exces- 
sive ramming, which is no doubt very often overdone ; 
the vigour of the British workman shows itself very 
often in the wrong direction. 

Then his remarks on the effects of cold are exceed- 
ingly interesting. I have always suspected, though 
I have never carried out any experiments myself, that 
certainly frost had a very evil effect upon all classes 
of concrete. 



4-'6 THE CONCRETE INSTITUTE 

Then with regard to his testing of floors ; there, 
again, he gives us some valuable hints, which I am 
sure we shall all of us take to heart. 

Then with regard to failures, he says they are very 
often due to shuttering and to strutting. That is, we 
know, very often the case. People are very often in 
a great hurry to remove their centering with very 
bad results, and his advice on that point is excellent. 

Then with regard to the education of the clerks of 
works and of men ; there I quite agree good work can 
be done by the London County Council if they will con- 
tinue the education, not only of the clerks of works, but 
also of the men who are engaged specially on this rein- 
forced concrete work. We all know in dealing with that 
class of work how absolutely important it is that every 
man should be doing his best in putting that concrete 
in, and should not shirk, otherwise disaster may follow. 
We can standardize materials, but, unfortunately, we 
cannot standardize men, and it is the personal element 
of the man that comes into our works so enormously, 
and the best design may be ruined by bad workman- 
ship. That none of us can escape from. Then with 
regard to electrolysis, I think the fear of it has been 
rather overdone. I think it is evident that, with decent 
care, ordinary care, that could easily be prevented, 
and I agree with the President that it is a question 
whether it does affect reinforced concrete to the extent 
that people imagine. 

Now, I also agree with him about the over- 
calculation business. Really, it is very often far too 
elaborate, and I absolutely and entirely endorse all 
that he says with regard to that. It really frightens 
one sometimes to go into the question of reinforced 
concrete because of the enormous calculations that 
have to be made, as he says, to the fifth place of 
decimals. It really brings reinforced concrete almost 
into discredit. 

Now, last of all, he speaks of the importance of 
failures. There, as a man getting on in years, as a 
man who has been an engineer for perhaps fifty years, 
perhaps more, I entirely agree with him. I personally 
have learned more by my failures than I ever did by 
my successes, and young men should take that to 
heart and not be ashamed when they make a failure. 
Of course, we rub it into ourselves when we do make 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 427 

a failure, and consequently we do not forget and we 
learn a great deal more by failure than we do by 
success. And in this class of work particularly with 
which this Institute deals we shall learn a great deal 
if members and others will let us know when a failure 
takes place, in order that we may make some investi- 
gations, and those investigations properly followed up 
will be of the greatest value to those who follow us 
in constructing work of that design. 

The address, as I say, covers an enormous amount 
of ground, and I felt while the President was reading 
it that with a man as our figure-head for the year 
to come of that stamp as our President this Institution 
is in safe hands, and when he lays down his year of 
office we shall be exceedingly sorry to part with him. 
I beg to move a vote of thanks to the President for 
his address. 

Mr. C. S. MEIK, M.Inst.C.E. (Vice-President of 
the Concrete Institute) : — Gentlemen, I have been 
asked to second the vote of thanks to our worthy 
President. Before doing so, I should like to express 
my hearty concurrence with all that he has said in his 
very lucid address, even to the extent of the cement. 
I also am quite at one with him in what he says about 
the workmen. Unless you get good workmen, you 
cannot do good work, more especially in reinforced 
concrete ; in fact, I would go to this extent and say, 
that for all reinforced concrete you ought either to 
train your own workmen or to be sure that you have 
not a man amongst them who has been accustomed to 
make concrete as it used to be made. The old- 
fashioned method of making concrete is, of course, 
quite out of place when you are dealing with material 
like reinforced concrete, and once get a labourer who 
has been used to the old style, you cannot get him to 
make good work in the new style. 

I also quite endorse all that the President has said 
about the necessity of making test cubes when you 
are carrying out important works. Irrespective alto- 
gether of making laboratory experiments, cubes made 
as the work goes on are of great value afterwards, 
should anything happen to the work. If a failure 
takes place, for instance, during testing, by referring 



428 THE CONCRETE INSTITUTE 

to the cubes that you have made on that particular 
day, you can find out whether the failure is due to the 
cement, or to bad workmanship, which settles the point 
and relieves your mind to a great extent when you 
find that the cement is not at fault. 

Now, as to the calculations, I quite agree with the 
President and Mr. Boulnois as to the necessity of 
simplifying calculations for this material as much as 
possible, and I would remark, what is the use of going 
to the fifth space of decimals, when you know, as I 
do from experience as the result of many tests, that 
the concrete itself varies as much as ioo per cent, in 
the same works, very often in the same day, due to 
different weather conditions or to different workmen ? 
Intricate calculations in a case like that are quite 
unnecessary and useless. 

Now, the President interpolated into his address 
a short statement about some tests that have been 
made by the Institution of Civil Engineers. I happen 
to be on the committee that made these tests, and I 
hope that the results will be published shortly. They 
have been delayed from unavoidable circumstances, 
but within the next few months I think they will be 
issued. The machine, if I may call it so, for making 
these tests is still available. A good deal of money 
has been spent over it, and the Institution of Civil 
Engineers have said that anybody wanting to make 
experiments the machine is at their service. The 
experimenter will, of course, have to make his slabs 
to suit the machine. It is not a toy machine, I may 
say, but one that will take in slabs that are in use 
every day, 15 ft. by 7 ft. 6 in., so that you get a 
reliable test of a slab that may be in actual use. The 
supervision of the tests will have to be carried out 
under the superintendence of some one appointed by 
the Institution of Civil Engineers. 

Now, I beg formally to second the vote of thanks 
to the President for his very able address, and ask you 
to express your thanks in the usual manner. 

Mr. E. FIANDER ETCHELLS (F.Phvs.Soc, 
M. Math. A.. A.M.I.Mech.E., M.C.I.) was asked'to sup- 
port the vote of thanks, and said : — The President 
speaks of standard notation. The Institute may cer- 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 429 

tainly congratulate itself on the fact that that notation 
has been adopted, both in schools and in books, and 
by official authorities, and by other technical institu- 
tions, to the exclusion of all counter-proposals, and 
if the same success follows the application of these 
principles to the formulas of structural engineering 
generally, then this Institute will have done something 
to benefit the next generation . For ourselves, we have 
learned the principal formulas that we are likely to 
require, and we will perhaps remember them in the 
old symbols, but there is another generation coming 
up, and engineering text-books will be very much 
simpler for them to follow. We do not know whether 
the extra time they will gain by finding the notation 
self-explanatory will be spent on sports, or on harder 
and more strenuous work in other directions. But 
that is for them to choose. We are giving them the 
time, they can dispose of the time how they think 
best. 

As an instance of the number of books which are 
springing up in which the notation has been used, 
some that occur to my memory are Adams and 
Matthews, Faber and Bowie, Markham, Cubitt, 
Andrews, and one just written by Osborne, and there 
are many more in the press. 

The President has also spoken about a committee 
which was to deal with the widening of the scope of 
this Institute, and he referred to it as the Improve- 
ments Committee. As chairman of that Improvements 
Committee, I would welcome any suggestions which 
the members have to make for the betterment of the 
Institute and the solidification of the profession. I 
would say to them : " Do not waste your grumbles on 
the desert air, but send them to me. I will lay them 
before the committee, and the committee will see what 
can be done to remedy the defects, if any." 

The President has also spoken about the title. He 
said that the sub-title is " An Institution for Structural 
Engineers and Architects." I would like it to be 
more than that ; I would like it to be truer to the facts 
and make it " The Institution for Structural Engineers 
and Architects," because it is the Institution par excel- 
lence for them. There is no other institution in this 
country which combines architects and engineers as 

FF 



430 THE CONCRETE INSTITUTE 

one corporate body, though there may be in Austria 
and in Germany. 

I also suggest that in doing that the David of 
the Concrete Institute is not in any way challenging 
the Goliath of the Institution of Civil Engineers, for 
the civil engineers have a far wider aim than structural 
engineering only ; they claim the whole of civil 
engineering, and structural engineering is just a branch 
and a part. The man who thinks that civil engineer- 
ing is synonymous with structural engineering is 
a man who holds a view of civil engineering which 
was far too narrow for the Council of the Institution of 
Civil Engineers and far too narrow for the founders 
of that Institution, the doyen of engineering societies 
throughout the world. Perhaps it may be in a rather 
distant future that the Institution of Civil Engineers 
itself will become an Institution of Engineers, as it 
would at once if it included military engineers, who at 
present were only accepted as associates. I desire that 
the Institution of Civil Engineers should cover the whole 
profession and ultimately include the Royal Engineers. 
Then engineering would be a profession as deep, as 
profound, as wide, and as dignified as the Army and 
the so-called learned professions of the Law and the 
Church. 

With regard to another point raised by our very 
practical President, the question of Fletton bricks, I 
utter a word of warning as to other bricks besides 
Flettons — namely, any bricks containing pyrites or 
other sulphur compounds. In the case of the Flettons 
the usual trouble is with a fossil known as the 
ammonite. A curly little thing it is, and it is mostly 
full of sulphur. It is frequently found in the Oxford 
clays, and it is a dangerous animal, even after it is 
dead. When it was alive its skeleton or shell was 
composed of calcic, calcareous, or silicious com- 
pounds, but long after its death the house that it had 
vacated has become filled with pyrites which have 
been deposited from percolating water. Frequently 
the original material of the fossil has been entirely 
removed. In organisms with calcareous skeletons the 
lime is readily dissolved by water containing carbonic 
acid. I have heard it said that brickmakers are to 
beware of clay containing ammonites. It is not the 



TWENTY-SEVENTH MEETING, Nov. 14. 1912 431 

ammonite which is the danger, it is the sulphur which 
fills his house after he is dead. 

Many of the fossils are composed entirely of pyrites 
in the form of ferric sulphide, having the formula 
FeS 2 , and this may lead to disruption of the concrete 
and consequential corrosion of the steel. 

With regard to another point, we have been told 
that we must not discuss a presidential address. It 
is one of the rules, but if I could discuss the presi- 
dential address, I would say that the deflection varies 
inversely with the elastic modulus and the elastic 
modulus of concrete increases with its age. If the 
concrete is new, the elastic modulus is rather low and 
the deflection is relatively high. Deflection is pro- 
portional to stress and inversely proportional to elastic 
modulus . 

The President has spoken about intricate calcula- 
tions, and he has spoken about them being introduced 
in certain official documents. In the first draft of 
the regulations which was issued to the technical 
societies the formulas were simple, but certain technical 
societies said : " Oh, no, we cannot have this ; this 
is empirical, this is approximate, this is inaccurate ; 
we want something that is exact and scientific " ; and 
so the building authority made them more scientific. 
But still the other side were not pleased then, and 
also when formulas which were simple were given side 
by side with the formulas which were complex the 
technical Press said : " Oh, strike out these simple 
ones ; they are not true ; they are not correct." I 
prefer simple formulas for the practical purposes of 
design. 

I suggest that this Institute might have a Formulas 
Committee, which would discuss and arrange simple 
formulas, which would be approximations to any official 
regulations or official reports which there may be. 
There is a Report of the R.I.B.A., but that Report 
has been made scientific because it was held that the 
function of the Committee was to set out the truth 
as near as they could, and it was the function of 
engineers engaged on the work to take such approxi- 
mations as they considered necessary or safe. One 
cause of the non-dissemination of simpler methods is 
that some people think, This or that is their particular 



432 THE CONCRETE INSTITUTE 

patent method. They discovered it themselves. They 
are not going to tell anybody else how they do it. 

Now, there are perhaps some hundreds of persons, 
all having what they call secret patent particular 
methods of their own discovery, but as soon as these 
are put into a standard form and notation it is found 
that they have nearly all the same method. In how 
many cases are approximations made with regard to 
the lever -arm of reinforced concrete tee-beams ? The 
exact equations are rather lengthy, but there is a very 
simple rule of taking the distance from the centre of 
the tensile reinforcement to the centre of the area of 
the slab. This is only just about the same distance as 
taking the overall depth of the rib of the tee -beam, 
measured from the underside of the slab to the under- 
side of the protective concrete or " cover." These 
two methods are very much quicker than the long 
formula?. Very many designers who speak darkly 
about their short methods if they would only come out 
and say exactly what they have done would realize 
that they are all nursing the same secret, except where 
they may be nursing diverse errors. 

In support of what has been said about the decimal 
places, I have had calculations submitted to me in 
which the thrust of coal in a large bunker showed so 
many tons and five places of decimals. With regard 
to the use of a larger unit, one of the great handicaps 
of the metric system has been the smallness of the 
units selected. The millimetre and the centimetre are 
too small for general use in buildings. If they would 
only use a decimetre it would be far better. I 
suggested that ioo lb. might be used as a unit. In 
1878 the British Government did advise the use of 
the cental (which was 100 lb.), and years ago I intro- 
duced 1,000 lb., which I called milal (from mille = 
1,000 and the suffix al = pertaining to) (analogous to 
cent-aV). 

Since then in America, kip has been used, a con- 
traction of kilo -pound, or 1,000 lbs. In the first draft 
of the regulations stresses were given in thousands of 
pounds, but suggestions were made that we should not 
use these new units, but give pounds. The building 
authority wished the regulations to be widely under- 
stood, and they accepted the suggestion. I do not 



TWENTY-SEVENTH MEETING, Nov. 14, 1912 433 

think it is a good suggestion, but if the technical 
societies wish the change, the onus and the labour is 
on their hands. 

With regard to the roof that has been mentioned 
in which there were about 100 sq. in. in the tension 
flange and they were 2 in. short, it is rather painful 
to realize that after they had put on this piece of 
2 by j, they still had not got the requisite area, because 
they had not allowed deduction for the rivet -holes. 
The precisionists failed in precision. 

The President had spoken of failures, and suggested 
that whenever a failure in reinforced concrete takes 
place the person should at once communicate with the 
Concrete Institute. I propose an amendment, and 
suggest that they should instanter communicate with 
the district surveyor, and when the building is shored 
up, they can then come round and tell the Concrete 
Institute how it happened. I would also like to rein- 
force what the President has said by pointing out that 
failures are not due to combining iron and steel, 
but are due to ignorance of mechanics, ignorance of 
chemistry, to the error of assuming the ends of a beam 
or pillar are fixed in theory when they are not in fact. 
I recently saw in the papers the case of the failure of 
a reinforced concrete mansion. There it was the 
mistake of cocksureness ; the occupants seemed to 
be holding a levee underneath the test load. Five 
persons were killed and ten others were frightfully 
injured. 

I also suggest that reinforced concrete should not 
be judged solely by the failures which have happened. 
Automobile engineering was not judged solely by the 
accidents which happened in the early days, when the 
cars were built higher and they overturned on going 
round corners. Aviation is not judged solely by the 
failures of aeroplanes or dirigibles. They built 
stronger aeroplanes, and with new men they made other 
and longer flights. Therefore we should not judge 
reinforced concrete practice solely by the accidents 
which happened in its days of youthful indiscretions. 
It is a material which can be dealt with by the 
ordinary laws of mechanics, supplemented by common 
sense — and a deal of common sense to make up for 
our ignorance of mechanics. 



434 THE COXCRETE INSTITUTE 

Coming more particularly to the more personal part, 
those who had known the President longest knew 
that he did use short methods of calculation ; they 
also knew that he could guess nearer than many men 
could calculate. A lot of it may be intuition, because 
he has the constructive instinct, but he has some very 
short methods of calculations which are worthy of 
being followed. Then also he has had long experi- 
ence in concrete work, for in 1878 he was building 
lighthouses, and some of those lighthouses are still 
standing, defying oceanic and titanic gales. 

Mr. BOULNOIS then put the motion, which was 
carried by acclamation. 

THE PRESIDENT :— I have to thank you very 
sincerely for the kind words that you have said about 
my address, and some of the points that have been 
raised, not in the shape of discussion, I trust will be 
taken to heart by the various committees later on and 
possibly before this time next year, when I have 
another address to read before you, I may refer to 
some of these criticisms by our friend Mr. Fiander 
Etchells . 

The Meeting then terminated. 



TWENTY -EIGHTH ORDINARY GENERAL 
MEETING 

Thursday, November 28, 19 12 

THE TWENTY-EIGHTH ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296, Vauxhall 
Bridge Road, London, S.W., at 7.30 p.m., on 
Thursday, November 28, 191 2. 

Mr. E. P. WELLS, J. P. (President) in the Chair. 

THE PRESIDENT (Mr. E. P. Wells, J.P.) :— 
Gentlemen, the only business that we have before us 
this evening is a paper to be read by Mr. Theobald 
upon " Bills of Quantities for Reinforced Concrete." 
I will now call upon Mr. Theobald to read his paper. 

Mr. JOHN M. THEOBALD, F.S.I. (Member), then 
read his paper as follows : — 



BILLS OF QUANTITIES FOR REIN- 
FORCED CONCRETE 

When I think of the papers that I have listened to 
at the meetings of the Concrete Institute on various 
occasions — papers of the highest technical interest to 
the members of your profession — I feel that I owe you 

435 



436 THE CONCRETE INSTITUTE 

an apology for venturing to read a paper the title 
of which concerns you only in the abstract, and not 
—may I say it? — in the concrete. In extenuation, 
however, I would mention that the reasons for my 
offence are twofold. In the first place, the title of 
the paper was supplied to me by our Secretary, and, 
secondly, because 1 feel very strongly that so revolu- 
tionary a suggestion should, in the first place, be 
submitted to the members of the Concrete Institute for 
their opinion before it is discussed — as it undoubtedly 
will be in the near future — at the headquarters of the 
members of my own profession. 

When a criminal pleads guilty, 1 believe the sentence 
is usually less severe than if he persists in denying his 
crime ; so that, if I am charged with holding a brief 
for the quantity surveyor, I at once admit the offence, 
but I shall endeavour to show that his employment 
will be advantageous to the interests of the client, of 
the architect, the reinforced concrete specialist, the 
contractor, and — anticipating an obvious comment — 
the defendant himself ! 

I trust it is unnecessary for me to say that, in reading 
this paper, I am making no reflection upon the quanti- 
ties supplied by the specialists under the present system, 
either upon the score of inaccuracy or otherwise. Such 
a charge would, of course, be quite unjustified and 
unjustifiable ; my criticism is solely directed against 
the system, and not against its exponents. 

Far be it from me to say a word against clients — our 
clients particularly. There is no class of men for 
whom I have a greater respect and admiration, but, 
like every one else, they have their peculiarities — one 
of which is conservatism. The client who is about to 
erect a building goes, in the ordinary way, to an 
architect to prepare the plans, and then either he, or 
his architect with his permission, employs a surveyor 
to prepare the bills of quantities, who, when the final 
account is presented, can be cross-examined upon the 
items ad nauseam, and whose life can be made a 
burden to him until the matter is settled. This is what 
the client likes ! This right of criticism gives him 
a sense of security and makes him feel he is getting 
value for his money f v with which, from personal ex- 
perience, I cordially agree ! ), and it is the absence of 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 437 

this facility for cross-examination that makes some 
people fight shy of availing themselves of the many 
advantages of reinforced concrete. This may strike 
you as being very absurd and unreasonable as, no 
doubt, it is — but the feeling of insecurity is there, and 
any means by which it may be lessened or removed 
are surely well worth employment. 

Lest you may think that this theory is an effort of 
my imagination, I may mention that, in my own ex- 
perience, I know of two buildings in which steel 
construction was used in preference to reinforced 
concrete solely for this reason. 

At the present time, when an architect decides to 
construct a building of reinforced concrete he sends 
a set of plans, sections, and elevations to one or pos- 
sibly more firms of specialists, who then submit a 
scheme of construction under their respective 
systems, together with an approximate estimate of the 
cost. The firm whose tender is accepted by the archi- 
tect then prepare their working drawings, which, with 
a bill of quantities (also supplied by them), are sent 
to the contractors, and the accepted tender is either 
incorporated by the quantity surveyor in the quantities 
sent to the general contractors or is the subject of 
a separate contract, as the case may be. 

Reinforced concrete, from the point of view I am 
taking to-night — that of the quantity surveyor — has 
but recently emerged from a healthy infancy ; but, 
now that its employment is being adopted on all sides, 
there is a feeling, not confined to the members of 
my own profession, that the specialist contractor should 
receive the same treatment as the builder, and it is with 
the grounds for that opinion that I propose to deal this 
evening. 

In advocating the claims of the quantity surveyor 
in connection with reinforced concrete, I am well aware 
that I shall be told that time does not admit of his 
employment, and that until the details are complete 
he would be unable to commence his work, and the 
delay thereby entailed might be considerable. I may 
say at once that I admit the objection, and my reply 
is that the client must wait. If the building were, let 
us say for argument's sake, a steel -frame building,, 
the steelwork details would have to be prepared, and 



438 THE CONCRETE INSTITUTE 

I am sure that I should be libelling the members of 
the Concrete Institute if I were to suggest that they 
take longer to supply their details than do the steel 
manufacturers. 

Of course, there may be cases in which rapidity of 
construction is everything. Under those circumstances, 
I say at once that the preparation of bills of quantities 
by a quantity surveyor is impracticable. He may still, 
however, be advantageously employed in the prepara- 
tion of a schedule of prices and subsequent measure- 
ment. It has been my experience — and I think all 
architects and engineers will agree — that the average 
client's conviction that the world will cease to revolve 
upon its axis unless his particular building is erected 
in an utterly impossible time is not warranted. It is 
only natural that he should require the work completed 
with the least possible delay, and a visit to quantity 
surveyors' offices at, say, eight, nine, ten, or even 
eleven o'clock at night should convince him that they 
fully recognise the necessity for " hustling." 

Under the present system the quantities issued by 
the concrete specialists, by their own showing, are 
prepared before the working details are complete, 
but granting the necessity (which I do not ), I 
admit that they are in a better position to do their 
work under these conditions than would be the quantity 
surveyor, by reason of their employment of constants 
and formulae of which he would have no knowledge. 
It must surely frequently happen, however, that in 
making the various details it is found necessary to 
alter the drawings from which the original quantities 
were prepared, and the latter are, consequently, inac- 
curate to that extent. 

I believe that under the present regime their 
correctness is not guaranteed, which, assuming for sake 
of argument that the drawings from which the building 
is subsequently erected differ from those from which 
the quantities were prepared, would seem to press 
unduly hard upon the contractor. I say the contractor 
because I consider the risk in this case is more likely 
to be his than the building-owners', as the alterations 
would more probably tend to increase the cost of the 
building than to diminish it. If I am wrong in my 
statement or the deduction I have drawn from it, I 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 439 

shall, of course, be corrected. It is obviously not 
a point upon which a quantity surveyor can have first- 
hand knowledge. 

The forms of contract under which reinforced 
concrete construction is carried out are, as far as my 
own experience extends, four in number : — 

1. The "lump-sum" contract, in which the 

contractor undertakes to erect ths building 
for a stipulated amount— no mention being 
made of the method of dealing with any 
variations that may arise during the progress 
of the work. 

Anything in the nature of a " lump-sum " 
contract of this description is, in my opinion, 
most unsatisfactory. As, however, I am deal- 
ing more fully with this particular form of 
contract under the next heading, I will merely 
mention that, unless a surveyor be employed, 
the contractor's account for extras has appar- 
ently to be accepted— his original priced bill 
of quantities not being accessible, presum- 
ably, without his permission. This form of 
contract would not be entered into in the 
case of an ordinary building, and I fail to 
see why any exception should be made in 
favour of reinforced concrete. 

2. The " lump-sum " contract in which the bills of 

quantities do not form part of the contract, 
but the contractor undertakes to deposit a 
copy of his priced bill of quantities, which, 
as regards prices only, is to form a basis 
for arriving at the value of any extra or 
omitted work. 

In a large reinforced concrete job upon 
which I was recently employed under this 
form of contract, there were various mis- 
takes in the bills of quantities— both for 
and against the building-owner— with which 
I was, of course, precluded from dealing, 
and one of the parties to the contract— I 
emphatically decline to state which profited 
thereby. 



44Q THE CONCRETE INSTITUTE 

I need hardly say that I am using this 
case solely to illustrate my point — the un- 
fairness of the " lump-sum *' contract — and 
not with a view to emphasising the possibility 
of errors in the quantities. Everybody makes 
mistakes, quantity surveyors among the 
number ; but in cases of error in the original 
quantities, the disability under which one or 
the other of the parties to this form of 
contract is placed is so obvious that I cannot 
understand why it is ever entered into. In 
a few cases, of course, there may be some 
reason for so doing, but speaking generally, 
I can find no argument in its favour. 

3. The "lump-sum*' contract, in which the bills 

of quantities form part of the contract. 

This form of contract has none of the 
disadvantages of the two previous examples. 
It is certainly fair to both employer and 
contractor, provided a competent surveyor is 
employed, but it relieves those responsible for 
the bills of quantities of all liability for their 
accuracy. If, however, as I said before, this 
liability is never accepted, the criticism, of 
course, has no point. 

4. The " lump-sum *' contract, in which the bills 

of quantities form a schedule only, and the 
entire building is remeasured. 

My only comment on this form of contract 
is that, unless under circumstances where the 
erection of the building in the shortest possible 
period is of vital importance, it seems need- 
lessly extravagant. It is quite possible, 
however, that the cost of the initial and 
subsequent measurements may not exceed the 
alternative cost of the preparation of bills of 
quantities and measurement of variations. It 
is merely a question of fees, upon which wild 
horses will not induce me to touch 1 



If, however, I urge the employment of a fully 
qualified quantity surveyor for the preparation of 
quantities for reinforced concrete, I do so even more 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 441 

emphatically when we arrive at the question of 
variations. 

It is apparently not usual for the concrete specialists, 
who prepare the original quantities, to settle the extras 
and omissions at the completion of the contract. I 
hasten to add that I am speaking from my own 
experience only, and if I am wrong in my conclusion, 
I shall doubtless be corrected. If I am right, I can 
only congratulate them on avoiding a tedious, and 
often unpleasant, job. The measurement of variations 
— I am again speaking personally only — is an acquired 
taste even when dealing with one's own bill of 
quantities, but in reinforced concrete, unless under 
these circumstances, it is anathema. 

Quantity surveyors, from bitter experience of varia- 
tions, have learnt to " take off " with a wealth 
of detail which would probably surprise you if you 
were to take the trouble to wade through their 
dimensions — a fate to which I would not consign my 
worst enemy. You would find that, whereas to the 
uninitiated the description of the item itself is com- 
prised in half a line of utterly unintelligible abbrevia- 
tions, a further two or three lines are taken up by a 
description of the particular portion of the building 
in which the item occurs. 

I remember on one occasion I endeavoured to 
describe to a friend of mine the precise nature of 
a quantity surveyor's business. I took a lot of trouble 
over the explanation because, for some inexplicable 
reason, he seemed interested, so I was encouraged 
to give him a description in detail, with which he 
appeared duly impressed. The impression, however, 
was hardly of the admiring character that I anticipated, 
as he merely remarked that it seemed to him quantity 
surveying was not so much a profession as a disease ! 
I have laboured this point, I fear, somewhat unduly, 
but I have done so for the purposes of comparison. 

A short time ago I was appointed by the building- 
owner to measure the variations on a reinforced con- 
crete building, with a firm of surveyors appointed by 
the contractor. The alterations were unusually drastic, 
and after a preliminary meeting, it was agreed that 
the specialists should be asked to lend us their original 
dimensions for the purpose of arriving at the omis- 



44-' THE CONCRETE INSTITUTE 

sions. Permission was, of course, readily granted, 
but upon the contractor's surveyor calling for same, 
he was shown a small sheet of paper on which, he was 
informed, were the dimensions in question. Further 
inquiry elicited the information that the dimensions 
from which these totals were obtained had been 
destroyed as being of no further use. 

Under these circumstances, of course, we had no 
alternative but to re -measure the omitted work to the 
best of our ability. Whether our measurements 
approximated to those originally taken is in the highest 
degree problematical, and whether the building-owner 
or the contractor suffered by the measurement will 
never be known. 

I am not taking this as a typical case. I do not say 
for a moment that it is usual to destroy the dimensions 
when once the totals are obtained, but I do say that 
engineers, by the very reason of their profession, are not 
in a position to take off the quantities for their work 
with the detail which contractors have a right to expect. 
The methods of the modern quantity surveyor are the 
outcome of three, if not four, generations' knowledge 
of the theory and the practice of his profession, and 
it has probably taken him between seven and ten years 
of constant application to acquire it. The education 
of an engineer — with which term I, of course, include 
the specialist in reinforced concrete — is even more 
arduous, and the exercise of both professions in the 
person of one individual requires a Superman ! 

Had I the good fortune to be an engineer instead of 
a quantity surveyor, I should welcome the opportunity 
of placing a laborious, and proportionately less 
remunerative, portion of my work upon other shoulders. 
That remark at least is unbiassed. 

Let us just see whether the employment of a quan- 
tity surveyor would have obviated any of the dis- 
advantages of the various forms of contract I have 
enumerated. 

In the first case, that of the '- lump sum " contract 
purely and simply, the measurement of the extras by 
him would, I venture to think, result in a greater 
degree of accuracy, and would probably be advan- 
tageous from the building-owner's point of view. I 
have never yet been refused access to a contractor's 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 443 

priced bills of quantities, even when I was not legally 
entitled to see them, and I do not think any con- 
tractor would refuse permission to a quantity surveyor, 
although he would probably — and quite legitimately — 
decline to hand them over to the building -owner 
himself. 

In the second case, that of the " lump sum " con- 
tract in which the quantities do not form part of the 
contract, his employment would be amply justified. 
For any shortage in the quantities he would be respon- 
sible to the contractor, and for any excess of measure- 
ment, to the building-owner. If I am correct in 
saying that no responsibility is taken at the present 
time, the advantages are obvious, both to the building - 
owner and the contractor ; while, assuming an error 
against the latter, the reinforced concrete specialist 
would possibly be saved a succession of unpleasant 
interviews. 

In the third example, that of the " lump sum " con- 
tract where the quantities form part of the contract, 
the advantages of the introduction of the quantity 
surveyor are chiefly confined to the method of " taking 
off " the original quantities and the consequent facili- 
ties for dealing with the variations. The responsi- 
bility is less, admittedly ; but I think any quantity 
surveyor worthy of the name would prefer to take the. 
responsibility for the accuracy of his quantities at, of 
course, a slightly increased fee to compensate him for 
the risk. 

In the last case, where the bills of quantities form 
a schedule only, and the building is re-measured, I 
rather fancy that no reinforced concrete specialist 
would be prepared to give the time to such re -measure- 
ment, and the quantity surveyor therefore gratefully 
takes the crumbs which fall from the rich man's table ! 

I do not know to what extent method of measurement 
may be taken as within the scope of my instructions, 
but I propose to touch briefly upon the point. I 
hope if there are any contractors present they will 
give us the benefit of their opinions, as it is a matter 
which directly concerns them, and the suggestions 
I have to make are purely in their interests. 

I have in my office at the present time a bill of 
quantities, prepared by a firm of specialists in rein- 



444 THE CONXRETE INSTITUTE 

forced concrete, for a building the cost of which runs 
well into five figures. It consists of three items- 
concrete, centering, and reinforcement. It is true the 
latter is subdivided into three items of rods or bars in 
various sizes, but beyond, presumably, an inspection 
of the drawings, this is all the information given to 
the contractor. 

With the greatest respect, I venture to say that no 
contractor, however experienced, can price that bill 
with any degree of accuracy, and I do not see how he 
can be expected to do so. I am not saying he will 
not make a profit on the job, but I do say that he has 
no idea what profit. I do not want to be told when 
I have finished that no contractor who tenders for a 
job, even when the quantities are issued from a sur- 
veyor's office, knows what profit he will make. That, 
of course, is obvious ; and he does know that he prices 
the bills on the assumption of a certain definite per- 
centage of profit, which he does not know in the case 
I have just quoted. 

Contractors, we all know, will price anything ; and 
this particular job has, no doubt, been priced on the 
" what I lose on the swings I gain on the roundabout 
principle, at a covering price to include all the cuttings, 
circular work, etc., that have not been measured. 

The time, however, has now arrived when bills of 
quantities for reinforced concrete should justify their 
existence and be, in fact, such as will enable the 
contractor to form an accurate idea of the work 
involved, which, in my opinion, he cannot do under 
the present system. 

In making the following suggestions as to method 
of measurement, I want it to be clearly understood 
that I am not laying down any hard-and-fast rules. 
They are only advanced with the idea of obtaining 
the opinions of members, and if I do not go as fully 
into this portion of my subject as I should wish, it is 
because I do not want to try your patience unduly, and 
because I also feel that it chiefly concerns the members 
of my own profession, and should, therefore, more 
fittingly be discussed in detail at either the Surveyors' 
Institution or the Quantity Surveyors' Association. 

The tendency under the present conditions seems 
to be to unite as many items as possible under one 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 445 

description. From my standpoint I plead' for a 
" separation order," and a fuller description of the 
work involved. 

In the first place all concrete and centering should 
be kept separate on the various floors. 

The concrete in walls, floors, beams, stanchions,, 
stairs, etc., should also be separated. I do not consider 
it necessary to further subdivide the concrete. The 
stanchions, for instance, if octagonal, circular, or 
circular on square — the beams if tapering — the stairs 
if Hewing — do not entail an additional labour (I am 
speaking, of course, of concrete only), and there is, 
therefore, no object in further separation. 

It is when I come to the question of centering 
that the present system of preparing bills of quantities 
leaves most to be desired. 

The prices of concrete and reinforcement are easily 
arrived at, and vary but little. From my point of 
view the centering is by far the most difficult item 
for a contractor to price, and it is, therefore, absolutely 
necessary that the description should be as full as 
possible and every variation and labour either measured 
or described. 

Commencing with wall centering — if circular it 
should be so described, and the radius given. Then, 
with regard to the vexed question of deduction for 
openings. I believe, unless very large, it has hitherto 
been the custom to assume the centering went across 
the openings, and, consequently, to ignore them. These 
openings should be deducted, and a numbered item 
taken of centering to openings of various widths and 
heights — averaged where not widely differing in size, 
but not otherwise. This item I have seen measured per 
foot run, but, as the chief cost is that of mjaintaining 
the supports of the wall centering in which the 
openings occur, it is essential that the contractor 
should have the actual sizes — an average of the same 
would be incorrect because misleading. 

Floor centering, of course, needs no discussion. I 
would only mention that all raking, or circular cutting 
and waste should be measured. 

The centering to beams should be measured per 
f'oot super — circular being, of course, kept separate — 
including all cutting at angles, etc. If the beams are 

GG 



446 THE CONCRETE INSTITUTE 

splayed on bottom edge, I should measure either 
" Extra labour forming splay blank width on edge 
of beam casing " ; '* Angle fillet blank width and 
fixing on edge of beam casing to form splay " ; or, 
take the item " Including all splayed edges " ; the 
latter, however, I consider unsatisfactory. 

If the beams are irregular or unusual in shape, I 
should keep the centering separate and give a sketch. 

The centering to small beams, say, 18 in. girth 
and under, I should measure per foot run. 

The centering to columns and stanchions should 
be measured per foot super, every variation in the 
shape being kept separate and fully described. I 
prefer to include all cutting in the description, but 
it can, of course, be measured separately, though I 
see no object in doing so. 

All extra labour, such as from octagonal to square, 

I should number as " Extra over centering for ' 

giving a full description. 

Centering to stairs should be measured per foot 
super, as " Centering to sloping soffit of stairs." If 
" rlewing," it should be measured separately. 

All edges of concrete floors, well -holes, sides of 
steps, etc., should be measured per foot run giving 
the thickness, but if 12 in. thick or over, per foot 
super. 

I need hardly say the description of all centering 
should include for ail necessary strutting up from floor 
below or otherwise supporting. 

The steel reinforcement being only of light bar, 
I do not think it necessary to separate the various 
weights on each floor. As, however, the prices of the 
bars vary according to size, I should, until experience 
taught me which sections could be added together, 
keep them all separate under a heading something 
like this : — 

The following in bar -steel reinforcement and 
hoisting and fixing at various levels (not exceed- 
ing blank feet from ground 1 . 

With regard to the question of bends, hooked ends, 
&c, I am of opinion that, where the bar reinforce- 
ment is of sufficiently small scantling to be bent cold, 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 447 

they can be fairly included in the description, the 
labour being so small that, if numbered, they are 
likely to disproportionately increase the price of the 
steel. Where, however, they have to be forged, they 
should be numbered. Stirrups and ties should be 
numbered, giving the diameter and length of the wire. 

I think it would be advisable, at the commencement 
of the bill, to describe such of the methods of measure- 
ment as might be open to misconstruction by the 
contractor, as, for instance, that all window openings 
have been deducted from the wall centering. This 
will probably only be necessary for a short time ; but 
until contractors have got used to our methods of net 
measurement, I consider that any information tending 
to lessen the risk of misunderstanding is wisely given. 

There are, of course, many items upon which I 
have not touched, but I have, I think, sufficiently 
indicated the principle of the method of measurement 
I suggest to enable you to criticise it. 

Should the employment of quantity surveyors become 
customary, it will undoubtedly lead to a greater degree 
of uniformity of method of measurement of reinforced 
concrete, as at the present time the acquaintance of 
my profession with yours is not of long standing. I 
hope, however, that this undesirable state of things, 
from our point of view, will shortly be remedied, when 
it is possible that you may find we may eventually 
prove a blessing in disguise, and even of some slight 
assistance to you, by relieving you of what I should 
imagine to be the least interesting portion of your 
work, and leaving you free to devote your time to 
that branch of structural engineering in which you 
have achieved such phenomenal success. 

I apologised at the commencement of this paper 
for introducing a subject which, from its very nature, 
could be but of indirect interest to you, and I repeat 
that apology now. It is, however, a question which, 
like the front of one of your reinforced concrete build- 
ings, will have to be faced, and you will do me the 
justice to admit that I have at least dealt with the 
matter as briefly as circumstances allow. My object 
has been to introduce the subject as shortly as 
possible, with a view to giving the maximum amount of 
time to the subsequent discussion, which cannot fail 



44« THE COXCRETE IXSTITUTE 

to be of very great interest to the members of both 
professions. 

Gentlemen, it only remains for me to thank you for 
listening to me so attentively, and to remind you that 
in England we have a proverb the concluding words 
of which are, " where angels fear to tread." (Applause 
and laughter. I 

DISCUSSION 

THE PRESIDENT (Mr. E. P. Wells, J.P.) :— 
Gentlemen, before the discussion is opened I wish 
to read a couple of letters that I have received, the 
first from Sir Henry Tanner, C.B., F.S.O., 
F.R.I.B.A., F.S.I., etc. (Past-President), which is as 
follows : — 

I quite agree with the principles referred 
to by Mr. Theobald. 

The practice of inviting design and tenders 
in open competition is, in my opinion, very un- 
satisfactory ; it leads to cutting down of the most 
vigorous kind, although the design may be within 
the limit laid down. 

' The quantities prepared by specialists are 
generally based on the French system, which is not 
very comprehensive in details. It is not unusual 
to find a staircase put down as one item, whether 
of stone or wood. This is not what we in 
England are accustomed to, and the results are 
difficulty in adjusting variations, and, I presume, 
in the majority of cases the building -owner 
suffers. 

The necessity of dividing the items men- 
tioned is of the greatest importance, because while 
the concrete and the steel can be ascertained 
definitely as a rule — not always — there is nothing 
to indicate the character of the false work. 
Therefore, while every care is taken, in regard 
to the first two items, to keep them within the 
total quantities provided, there is no interest what- 
ever in keeping down the false work. Conse- 
quently, when a flat slab might be made to meet 
the case by a small addition of concrete, the 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 449 

builder has to case round raking struts projecting 
on either side. The raking, cutting, and waste 
involved are patent to any one. 

" There is another matter having very serious 
results on the progress of the work, and that is 
multiplication of sections differing by 32nds of 
an inch in diameter. The mills cannot be got 
to put in rolls for the small quantities involved, 
whereas there would be no difficulty if pains were 
taken to add a little to some and take off a trifle 
from others and adjusting distances apart. 

; ' Under the present system the delays that 
take place at the commencement are appalling. 
The drawings showing the plans and sections, 
and generally the positions of the beams and 
stanchions, are prepared by the architect, and, 
together with a specification and conditions of 
contract, are supplied to persons indicating their 
desire to tender. This labour will be appreciated 
by architects, and adds considerably to their 
expenses. With the tenders are supplied some 
calculations and a few typical details ; and the 
contract having been secured after examination 
of these details, you are at the tender mercy of 
the specialist, and he suits himself on the con- 
tingencies of his business as to the supply of 
the rest. It is the builder who is answerable to 
the building -owner, and the specialist can gener- 
ally shuffle out of any responsibility to his 
nominee. The consequence is that the ordering 
of steel is delayed, and the time allowed to the 
mills is altogether insufficient in normal times. 

" In my opinion, the specialist, like the archi- 
tect, should be ready with the whole of his 
drawings, and the quantities should be properly 
prepared by a surveyor on the English system. 
How far the rods should be divided into sizes 
is a matter rather depending upon price per ton 
than on any other basis, but hoisting certainly 
has some small effect. I dare say the builder 
would put one figure to the lot, but he has the 
option of doing otherwise. The rod diameters 
should be as few as possible, and the false work, 
and hence the concrete placed in the forms, as 



450 THE CONCRETE INSTITUTE 

simple as possible. I do not believe in varying 
the proportions of the cement ; this leads to 
difficulty and increases the responsibility of the 
clerk of works, and when one considers that in 
three or four months the concrete has perhaps 
doubled in strength, there is no need for such 
niceties and differentiation. 

" If reinforced concrete building is to become 
popular it must be made as simple as possible, 
which means economy, and generally is entirely 
advantageous . 

" My remarks have wandered somewhat from 
the scope of the paper, but still, they all bear 
on the method to be pursued in tendering. I have 
had experience of obtaining tenders on the basis 
of general drawings and quantities, omitting the 
competition for design, and these have shown very 
good results — as good if not better than those 
obtained when competitive designs and tenders are 
resorted to. This latter system does not allow the 
liberty of alteration that the former is capable of. 

" I beg to thank Mr. Theobald for bringing 
forward the subject, as, in my opinion, the change 
is a fundamental one and must come." 

The next letter that I am reading to you is from 
Mr. W. E. H. BURTON, Assoc. M. Inst. C.E., M.C.I. 
He says : — 

" I am much obliged to you for your letter 
enclosing me copy of the paper to be read by 
Mr. J. M. Theobald on " Quantities for Rein- 
forced Concrete." 

" I have read the same with much interest, and 
regret that I shall not be able to be present at 
the meeting ; however, I have pleasure in 
appending a few general remarks on the same. 

" If Mr. Theobald's paper results in the 
quantity surveyor becoming duly recognised as 
a necessary agent in the carrying out of works 
on reinforced concrete, it will inaugurate a new 
era that will be hailed with delight by architects 
and contractors alike. Under the present system 
it is wellnigh impossible to secure satisfactory 
competitive tenders. The number of items in 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 451 

the quantities issued by concrete specialists is 
too meagre to admit of a contractor forming a 
complete idea of the work required to be done. 
The labour in bending bars and placing the re- 
inforcement varies much in the different systems 
and is a very uncertain factor, and is often mis- 
leading to contractors who have not had experi- 
ence in the particular system ; hence such 
disproportionate tendering. Again, variations 
appear almost a sine qua non, and without a 
carefully drawn -up schedule of quantities an 
equitable settlement cannot be arrived at. 

" Quantity surveying has become a science only 
acquired by years of training and experience, 
and taking off quantities for reinforced concrete 
will call for still further attainments on the part 
of its practitioners. It will mean that they will 
have to give reinforced concrete a closer study, 
and be, at least, capable of checking the various 
schemes they handle, and advising the architect 
upon matters of construction and detail. 

" On the other hand, the quantity surveyor will 
require the engineer who formulates the scheme 
to supply him with an infinitely greater number 
of drawings, particularly large-scale details, than 
have been considered necessary in carrying out 
such work in the past. 

" Incidentally, it will probably lead to more 
engineers designing their own reinforcements, and 
not relying so much on the so-called specialists. 

' The result will be to secure contractors a 
fairer basis upon which to tender, clients full 
value for their money, the architects more facili- 
ties in settling up accounts, and thus forward the 
use of reinforced concrete ; and our thanks are 
due to the author for this able introduction of 
the subject." 
Now, gentlemen, I will call upon Mr. Alban H. 
Scott to open the discussion. 

Mr. A. ALBAN H. SCOTT, M.S. A. (Member of 
Council): — Mr. Chairman, you have done me the 
honour of asking me to open this discussion. First 
of all, I think the thanks of this Institute are due to 



45- 1 THE CON'CKETE INSTITUTE 

Mr. Theobald for so kindly placing this matter before 
us. I am an architect, but I have also had professional 
training as a quantity surveyor, and it is incompre- 
hensible to me how surveyors — and, indeed, archi- 
tects and builders — have allowed certain firms calling 
themselves specialists to override and upset a custom 
which has been in the building trade so many years. 
In the majority of cases the method of tendering for 
reinforced concrete work has reverted to the unsatis- 
factory one in usage previous to the last forty or 
fifty years. 

Sir Henry Tanner's most useful and instructive letter 
mentioned one point with regard to architects inviting 
or receiving competitive schemes from specialist firms . 
Personally, I think that if an architect did such a 
foolish thing as to receive competitive schemes from 
these firms and any defects occurred in that building 
when erected, the architect would be held responsible 
for negligence. In my opinion, it is against all public 
policy and entirely against the building-owner'.- 
interest to do such an absurdity. In no other form 
of construction would you adopt this method unless 
you were shirking your duty and inviting trouble. If 
you are asking for tenders for steelwork the architect 
shows on his plans full particulars as to sizes, joints, 
and weights, and the surveyor puts these into proper 
bill form, and your contractors all tender on the same 
basis. An architect is employed to look after his 
client's 'the building -owner's ) interests, and he cannot 
do this if he throws the responsibility for a portion of 
the work on to some other person, that person being 
free from legal responsibility to the building-owner. 

If the whole question were not so serious, the atti- 
tude taken by some architects towards the firms re- 
ferred to would be almost humorous. It is a most 
serious matter for the building-owner, and it is finan- 
cially equally so for the surveyor. An architect loses 
all caste by dealing with them in the way that many of 
his profession do. He throws — as far as he can— the 
whole responsibility on to them, but by so doing he 
does not get rid of his legal responsibility when he 
employs these people either direct himself or through 
a building contractor. 

Quantity surveyors, perhaps, to a certain extent, 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 453 

have invited this position in failing to make them- 
selves thoroughly acquainted with reinforced concrete 
construction. It is astonishing to watch the peculiar 
development. Certain firms specialising in reinforced 
concrete come over here and they immediately take 
the successful attitude of collaring the builders by 
getting them to pay for licences ; and this is the 
reason, I think, that the builders to-day are willing 
to put up with the inconveniences, losses, and possible 
gains of tendering on — we will not call them quanti- 
ties, we will say, tendering on a statement, not neces- 
sarily a correct statement, as to certain material which 
might be employed on the building. 

if you put such quantities or particulars in front of 
a builder for any other construction than reinforced 
concrete work he would not look at them ; he would 
say it was so absurd to ask for tenders on such 
information. The " statements " generally show all 
the weight of steel rods together. Steel rods of half 
an inch diameter and under cost anything up to thirty- 
five shillings a ton extra over the basis price. The 
method of lumping the concrete is equally as bad. 
Steel, concrete, and centering fixed in different posi- 
tions have an entirely different value, and in the bill 
must be kept separate. 

There is another big responsibility which affects 
quantity surveyors, too. Architects are bound legally 
to give their best professional services to their clients, 
and they are not giving these if they employ other 
people to do some of their part of the work. It also 
affects the quantity surveyor in this way — that an 
architect is responsible to his clients if he does not 
adopt the usual method and employ a quantity sur- 
veyor for reinforced 'concrete work, the same as for 
other work ; and for any trouble that might arise under 
a building contract, owing to his departure from the 
usual or established method, he is certainly morally, 
and I believe I am right in also saying legally, 
responsible, for which he has only himself to blame. 

It is astonishing that a responsible architect to-day 
should accept the quantities from these specialists. I 
say " astonishing" for this reason — these persons are 
taking up work for which they are not qualified, and 
they know they are not qualified. They do not as a rule 



454 THE CONCRETE INSTITUTE 

employ men who have had training as quantity sur- 
veyors ; they have assistants who have a splendid 
education in mathematics, and are probably good 
engineers ; but as to quantity surveying, they know 
nothing at all about it, and never will unless they 
undergo the usual long and arduous professional 
training. 

Mr. Theobald puts another statement forward here. 
He says that he knows of two buildings in which steel 
construction was used in preference to reinforced con- 
crete solely for the reason that the architect could 
employ a quantity surveyor. 

Now, this is surely a serious question for the archi- 
tect. If an architect were employed and he were 
conscientiously of opinion that reinforced concrete was 
a more suitable form of construction for the particular 
building, then he would be legally liable to his clients 
for not having done that building in reinforced concrete 
work. I do not think there can be the slightest 
question about that. 

Usually speaking, specialists do not attempt to 
guarantee their quantities — in fact, when anything goes 
wrong, they do not even attempt to justify them, but 
state that they are not infallible. 

On page 439, under the heading of " 1," the paper 
goes on to state that " unless a quantity surveyor be 
employed the contractors' account for extras has appar- 
ently to be accepted " ; but surely whether there are 
quantities or not, or schedules of prices or not, any 
extras from a contractor can be examined in detail, and 
must be dealt with on correct measurements and at 
reasonable prices. 

The author states in the next item that a certain 
form of lump sum contract is not quite a fair one. 
I think that any contract is fair if it is entered into 
by two sane people and provided that there is no 
undue pressure exercised on either party on entering 
into that contract. 

Mr. Theobald seems to imply that he is rather ^ exed 
with these people, not so much for taking out their 
quantities but because they do not settle up the varia- 
tions. If you assume it is necessary for them to take 
out the quantities, I do not think I would like to 
trust my clients or myself to the tender mercies of 



TWENTY-EIGHTH MEETING, Nov. 2$, 1912 455 

firm's specialising in reinforced concrete to deal with 
the accounts or variations. 

On page 444 of the paper the author deals with the 
subject of contractors' pricing for reinforced concrete 
work where lumped quantities are provided. The con- 
tractor, I am sure, does not desire to tender on lumped 
quantities, but he seldom has any alternative. There 
are, however, other kinds of contractors ; firstly, those 
who take, and are quite pleased to take, any loose 
form of quantities or contract because it gives them 
ample chances of making up claims. The term 
" claims " is used, not in its relation to variations of 
measurements or prices but in its wider sense ; 
secondly, there are the really good sportsmen, who 
have their bill of quantities forwarded probably 
through a responsible architect, and they tender for 
the work out of respect to him and know that they 
will be fairly dealt with by him ; and, lastly, there 
are the contractors, who do not keep analysed prime 
costs but rely on a broad experience to teach them an 
approximate overall price. 

Reverting to the question of claims, there are many 
points that come up under this heading. For instance, 
in one case we had to deal with, it might interest you 
to know how one of these claims was made up. On 
the I -in. scale drawings which were prepared before 
the stresses and strains had been worked out, by some 
extraordinary coincidences the sizes of the beams and 
other members had generally been shown in widths 
of 6 in. and multiples of 6 in. When the accounts 
came to be settled up the contractor claimed the cost 
of extra cutting of all his centering because the sizes 
adopted in the building were not multiples of 6 in., 
and he stated that he had arranged his pricing on the 
assumption that 6-in. widths could be used all through 
without cutting. 

As a counterblast to that absurd claim the building- 
owner insisted upon a counter-claim being put in for 
the cost of the omission of concrete in the space 
occupied by the steel. In the job in question 
that amounted to no less a sum than £66, which is 
quite a considerable item. I hesitate to believe that 
you could ever justify in a court of law the principle 
of measuring concrete where that space is occupied 



456 THE CONCRETE INSTITUTE 

by another material. I do not think the question of 
custom could be claimed, because there is no custom 
existing as to the method of measuring reinforced 
concrete work, quantity surveyors having failed to 
establish one ; so I think that the question of the 
deduction of the concrete where steel is used can be 
raised and can be enforced. I do not say it is 
desirable. Further, on the same question I notice 
Mr. Theobald advisedly uses the term " all dimensions 
are net." You cannot call dimensions " net " when you 
measure for two materials to occupy the same space. 

Another expression used by the author is, " When, 
however, the bars have to be forged they should be 
numbered." I hope the surveyors will never measure 
that item in reinforced concrete work. I have yet to 
find a responsible architect who would allow forging 
in rods used in reinforced concrete work. Forging 
should never be done ; it is rather a pity it should 
be put in the paper as even a possible contingency. 

From one statement made in the paper one is led 
to think that the author is under the impression that 
the Concrete Institute consists only of people who 
are pleased to call themselves reinforced concrete 
specialists ; but although there are a few specialists, 
it has a number of architects, surveyors, and a good 
many engineers ; and no matter how much or how 
little these know of reinforced concrete construction, 
none but the " specialists " desire to be called anything 
but architects, or surveyors, or engineers, as the case 
may be. 

I do not want it to be understood that the Concrete 
Institute is limited to those known as reinforced con- 
crete " specialists " who are in many instances mainly 
steel-merchants. Some of the " specialists " are my 
personal friends, but the attitude they are taking to- 
day towards architects, surveyors, engineers, and con- 
tractors is a little beyond a reasonable man's endurance, 
and it is certainly against the interests of the building- 
owners. 

In conclusion, I would like to refer you to the 
Articles of Association filed by some of the' specialists. 
I think you would be very surprised to find that steel- 
work and other trades are associated with almost 
every profession under the sun. 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 457 

Will you allow me to propose a most hearty vote 
of thanks to the author of this most interesting" 
paper. 

Mr. T. A. WATSON, M.C.I. :— Mr. Chairman and 
gentlemen, some few days ago, to my sorrow, I 
received an invitation from the Secretary to take part 
in the discussion to-night. Not being a particularly 
good speaker, I am afraid it will be to your sorrow 
also . However, I appreciate the honour, and will 
endeavour to say a few words. The author of the 
paper has, I consider, given us a particularly happy 
one. He has dealt with the subject in a very breezy 
manner and practically settled it all offhand. 

The condition of affairs that exists at the present 
time between the quantity surveyor, the architect, and 
the contractor is the natural outcome of the introduc- 
tion of reinforced concrete into this country. That it 
is bad in some respects there is no doubt, and it should 
be remedied, and the method which the author suggests 
is, in my opinion, a very happy one. 

I particularly like the phrase in his paper in which 
he says, ' The clients must wait." I think that, 
at the present time, there is far too much undue 
haste in the preparation of reinforced concrete 
schemes, and sufficient time is not given to the con- 
tractor or the reinforced concrete specialist to prepare 
and price the various schemes ; and anything which 
will tend to give more time to the contractor and to 
the reinforced concrete specialist will be, in my 
opinion, a boon, even if it extend to the waiting of 
the client. There is one thing which Mr. Theobald's 
suggestion, if it is carried out, means, and that is 
practically the abolition of competition between various 
reinforced concrete specialists, and I think that is 
a very good thing. As far as I can see, if 
Mr. Theobald's scheme is carried out, the architect 
or the building-owner will have, first of all, to decide 
on a firm of reinforced concrete specialists to carry 
out the work, or an engineer to design the work, and 
that, I consider, is something very useful gained. 

AX HON. MEMBER :— So he ought. 

Mr. WATSON : — The present-day system — from 
which I have suffered, and my firm as well — in which 



458 THE CONXRETE INSTITUTE 

we have been invited to tender on four or five schemes 
drawn up by different " specialists " for one particular 
job, means that we have to price one job four or five 
times over, and then perhaps not get it ; and we have 
had the expense of this extra labour, that might have 
been saved had the course suggested by the author 
been adopted. 

There are some difficulties in the way of carrying 
out the scheme, one of which is the difficulty that the 
reinforced concrete specialist or the engineer will 
have in preparing detailed drawings of the work 
in time to satisfy the client, and in time for the 
quantity surveyor to take off his necessary particulars, 
because the details of reinforced concrete are very 
considerable, and the number of bars and the number 
of bends in the bars and the weight of the bars neces- 
sitates a lot of arduous work on the part of the 
engineer, more so than it does in steelwork construc- 
tion ; and if the building is in a hurry, I am afraid 
that the only method of dealing with the reinforced 
concrete quantities is by the suggestion which Mr. 
Theobald has numbered " 4 " — i.e., a lump-sum con- 
tract in which the bills of quantities form a schedule 
and the entire building is re -measured. The author 
says that unless under circumstances where the erec- 
tion of the building in the shortest possible time is 
of vital importance, this method seems needlessly ex- 
travagant. With this I cannot agree. I think, 
undoubtedly, it is the best way, it is the simplest 
way, it will expedite the work, and it really brings 
no hardship either on the contractor or the reinforced 
concrete specialist, because it gives the " specialist " 
the necessary time in which to prepare proper working 
plans and detailed drawings, while the quantity sur- 
veyor is taking out approximate quantities from pre- 
liminary rough plans previously prepared by the 
engineer or reinforced concrete specialist, giving the 
weights of bars, sizes of beams, etc., sufficient to 
enable the quantity surveyor to take off approximately 
the correct amount of steel and concrete. 

As regards the latter part of the paper, the method 
of taking off the quantities, on that I have nothing 
to say. The quantity surveyor is an expert in taking 
off centering, and I have no wish, and I do not sup- 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 459 

pose any reinforced concrete specialist wishes, to take 
that work from the quantity surveyor. 

I should like to congratulate Mr. Theobald on and 
thank him for his paper ; it is one which I have 
listened to with very great interest. Before sitting down, 
I should just like to say a few words with regard to 
what the last speaker said. The last speaker has spoken 
in anything but respectful terms of the engineer. 

Mr. SCOTT : — I said the reinforced concrete 
specialist. I did not say the engineer. They are 
two different persons entirely. The engineer I call 
a professional man ; I do not call the " specialist 
a professional man ; he is in many cases in reality 
merely a dealer in steel. 

Mr. WATSON : — Seeing I misunderstood the 
gentleman, and the character of the engineer is 
cleared, I do not think I will take up the cudgels 
on behalf of the reinforced concrete specialist ; I 
will leave him to do that himself. The last speaker 
also attacked his brother -architects, and I think that 
they should not be slanged quite so much, if I may use 
the expression, because I really think that the present 
condition of affairs is merely the natural outcome of 
the adoption in this country of reinforced concrete, 
adopted because it was a more economical form of 
construction in many instances than the construction 
that obtained in the days before its adoption. Gentle- 
men, I thank you very much for listening to me ; I 
did not intend to say so much. 

Mr. A. G. CROSS, F.S.I., Hon. Secretary Quantity 
Surveyors' Association : — Mr. President and Gentle- 
men, I must first thank you, Sir, and the Council of 
the Institute for inviting me to be present to hear Mr. 
Theobald's paper. As Mr. Watson says, Mr. Theobald 
practically settled every question for us. There is 
one point I do not think he sufficiently emphasised, 
and that is the advantage which accrues to the 
building-owner from the employment of the quantity 
surveyor. After all, it is the building-owner who 
provides employment for the architect, the engineer, 
the quantity surveyor, or the " dealer in steel " ; and 
his interests should be our first consideration. 



460 THE CONCRETE INSTITUTE 

I am afraid it is a little difficult to persuade the man 
in the street that, in advocating a continuance or an 
extension' of that system by which he lives, a quantity 
surveyor is absolutely unbiassed ; but I think the fact 
that the system of contracting on quantities has pre- 
vailed pretty generally for the last hundred years is 
sufficient evidence that it is appreciated. In my 
opinion, an inestimable advantage accrues to the 
building-owner by the employment of the quantity 
surveyor, and the quantity surveyor having been 
employed, it is his duty to see that quantities for 
every item embraced in the building or engineering 
structure upon which he may be engaged are pro- 
vided. By no other means can the value of artificers' 
work be accurately estimated ; in fact, the surveyor's 
opinion upon any question of value is usually worth- 
less until the quantities are prepared for the particular 
building. In my view, there is nothing in either the 
workmanship or the materials of a reinforced concrete 
structure which, from its nature, cannot be measured 
and its value estimated by the surveyor's usual method 
of picking a completed building to pieces and 
measuring each item of which it is constructed. 

Another argument in favour of the employment of 
the quantity surveyor is that the provision of a bill 
of quantities usually results in a lower estimate being 
obtained. This in itself is of advantage to the 
building-owner, although we have heard it contended 
— I think Sir Henry Tanner does so in his letter to- 
night — that any system which tends to increase the 
competition for a method of construction which relies, 
as this does, upon the use of the best possible material, 
and of the best workmanship, is to be deprecated. 

Some people appear to be apprehensive lest the 
extension .of competition for this method of construc- 
tion may result in the work being undertaken by the 
general contractor to the effacement of the expert 
and the specialist, by whom, in my opinion, this work 
should be undertaken. I do not think there is any 
ground for any uneasiness on that score. At the 
moment there are very few general contractors who 
would care to undertake this work without the inter- 
vention of a specialist, and those who do so would 
probably sublet the work to those who specialise in 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 461 

this form of construction, or else would have in their 
employ assistants who are skilled in its construction, 
under whose supervision the work would be carried out. 

The introduction of reinforced concrete into this 
country seems to have caused as much consternation 
as did the spread of Christianity among the silver- 
smiths of Ephesus, when Demetrius, finding his craft 
imperilled, called a meeting of his fellow-craftsmen 
and proceeded to create a terrible uproar. I have 
this, sir, on the authority of St. Paul. 

I think we are only repeating the experience we 
gained between the time when steel construction was 
first introduced and the time when its use became 
general. For some years it was the rule rather than 
the exception to get a price from a steel -construction 
contractor and include that in the builder's tender 
without any quantities and without any competition ; 
but gradually that system has been superseded by the 
practice of the quantity surveyor preparing the quan- 
tities for steel construction, and the items being 
included in the general bill in the usual way. 

The system adopted by an architect with whom I 
have been associated for many years with regard to 
steel construction is this. He always has the quanti- 
ties prepared, and the bill added to the general bill 
in the usual way, a proviso being inserted that the 
steel construction is to be carried out by one of the 
following firms — enumerating half a dozen leading con- 
tractors who specialise in steel construction. The 
builders in that case would naturally invite competitive 
tenders and accept the lowest. It seems to me, Sir, 
if that system were adopted with regard to reinforced 
concrete that the objections of those who are afraid 
that the work will be carried out by those who are 
least competent to do it will be overcome, and the 
building-owner should at the same time secure a certain 
amount of competition for the work for which he is 
paying. 

I think there are very few other points upon which 
I propose to touch in Mr. Theobald's admirable 
paper. He had something to say about alterations 
and variations. I always thought that this particular 
system of construction did not lend itself to altera- 
tions. Now, I quite agree with him that unless the 

HH 



462 THE CONCRETE INSTITUTE 

quantity surveyor is to be provided with the original 
dimensions from which the quantities have been 
prepared 

A MEMBER :— If they are not burned. 

Mr. CROSS : — If they are not burned his work 
would certainly be, as he described it, an acquired 
taste ; in that respect, I presume, he suggests that 
it would resemble, shall we say, Astrakhan caviare, 
or olives, Browning's poetry, or Meredith's novels. 

In conclusion, I should like to congratulate Mr. 
Theobald on his paper, and to again thank you for 
allowing me to be present this evening. 

Mr. S. BYLANDER, M.C.I., Chairman of Junior 
Institution of Engineers : — Mr. Chairman, I am afraid 
I have very little to say on the subject, which I know 
so little about. I never attempted to make any quan- 
tities, but I have seen a good many. There is one 
thing which I believe to be of very great importance 
in regard to the engineer and contractor (and I am 
sure also the architect ) — that is, a " system of 
simplicity." 

Now, gentlemen, we have a chance of making a 
standard and forming a standard without basing same 
on precedent, and I think that we should try to make 
it as simple as possible. How this can be done I 
am not prepared to say, but when I first saw the 
quantities for reinforced concrete prepared by a 
specialist it occurred to me it was made in a very- 
simple way — namely, unit prices or unit quantities. 
I think that could be adopted with advantage. For 
instance, so many square feet of floor at certain thick- 
ness and so many foot run of beams of certain sizes. 
I also think that we might, in the quantities, state the 
weight of steel per foot run instead of the total weight 
of steel. We might also state the number of bends 
per ton of steel, also, of course, stating the size of 
the bars. It is very convenient for contractors, I think, 
to price a bill of quantities which contains as few 
items as possible ; still, the different items should 
be separated so that they could be properly priced. 
As the author explained, this is particularly a question 
of difference in cost. Centering: for curved work and 



TWENTY-EIGHTH MEETING. Nov. 28, 1912 463 

straight work should be kept distinctly separate. The 
size of beams, of course, affects the cost of centering 
per square foot ; therefore the size must be given of 
the finished member. 

With regard to separating the items for different 
floors, I do not think it is so necessary, perhaps, for 
an ordinary sized building, but it is very useful to 
have the different quantities just the same. 

I am in hearty agreement with Mr. Watson and his 
suggestion that quantities for reinforced concrete 
should be taken out provisionally, and the prices to 
form a basis of future remeasurement. I think that is 
an exceedingly practical way of dealing with rein- 
forced concrete. I appreciate, being an engineer, how 
very necessary it is that you should have sufficient time 
to prepare the necessary details. In reinforced con- 
crete more than any other constructional work, I think, 
it is necessary that the drawings should be complete 
and clear. 

In conclusion, I think I shall ask the quantity 
surveyor, when he finally prepares his quantities, not 
to forget one thing, and that is to provide a provisional 
sum for the payment of an inspector or a clerk of 
works, properly qualified and certified by the Concrete 
Institute to be capable of seeing that the work is 
carefully carried out according to drawings and good 
practice. Then I do not think we need be afraid 
of putting the work out to competition to different 
contractors for fear of unsatisfactory work. 

MR. T. E. BARE, Vice-President Quantity Sur- 
veyors' Association : — As a quantity surveyor. Sir, 
I naturally sympathise with my friend Mr. Theobald 
in the views he has put forward in his paper. I 
think we might all assume that everybody will be 
better off by the employment of quantity surveyors 
when tenders are required for reinforced concrete and 
for the proper adjustment of varied or extra work. 
The chief difficulty seems to me to be the question 
of time, if it should be really necessary to wait for 
completed details before quantities could be prepared, 
particularly with regard to the steel reinforcement. 
Sir Henry Tanner referred to this question of delay 
in his able remarks upon Mr. Theobald's paper which 



464 THE CON'CRETE INSTITUTE 

have been read to us. I rind, however, the method 
which has been in common use in quantities issued 
by specialists is to give the weight of steel, calculated 
approximately at so many pounds per unit, whether it 
be per square yard of floor or per foot run of beam, 
and so on. Such given weights, presumably, are based 
upon known constants of work actually executed or 
from elaborate mathematical tables to which the 
engineer or specialist refers, but certainly not upon 
the actual quantities of steel " taken off " from the 
detail drawings. It is to be supposed that these fixed 
weights, per unit, which are not subject to any re- 
adjustment, err, if anything, on the right side for 
the contractor ; but it might possibly be the other 
way, and I would suggest with regard to the steel — 
and, perhaps, the steel only — that provisional quanti- 
ties should be given in the bills, calculated, in the 
same way, from constants figured upon the drawings 
of the general scheme, and we should not then be 
in a difficulty with regard to the detailed drawings not 
being prepared in time. I think that a fair estimate 
of the amount of steel that would be required could 
be arrived at in this way. 

Well, then, at some time or another, I was going 
to say, it would have to be clearly stated what steel 
is required. For instance, I suppose that on each 
detailed drawing there would be a schedule given of 
the steel required for each particular section of the 
work, and, indeed, such schedules must go to the 
manufacturer so that the steel for each section can 
be separately delivered in bundles, it being impossible 
to sort steelwork out if it were delivered pell-mell. 
In that way it would be easy afterwards and at leisure 
for the quantity surveyor, from the details, to ascer- 
tain the weight of the steel that had been actually 
used, and I think that is one way of getting over the 
difficulty. 

I think as regards other matters in Mr. Theobald's 
paper, the gentlemen who have previously spoken have 
anticipated what I had to say. One thing, however, 
I would say, and that is in all probability, if you give 
the quantity surveyor the job, the contractor would 
get a better presentment of the centering required 
than he now does, which seems to me to be a very 
important thing. 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 465 

Mr. W. G. PERKINS, District Surveyor for Hol- 
born 1 Member of Council) : — Sir, there are many quan- 
tity surveyors here present to-night, and I think they 
could deal with this question better than I can, but I 
should like to criticise the remarks of one or two of the 
speakers. The last gentleman has suggested that you 
should ascertain the amount of steel in a job by 
the use of constants. That would be all very well 
if the quantity surveyor described or gave the amount 
of concrete used in so many square feet of a certain 
sectional area. But I do not think he does that. 
He puts it into feet or yards cube, and we do not base 
our percentage of steel upon the cubic yards of rein- 
forced concrete, but upon the sectional area of the 
beam or the slab with which we are dealing. For that 
reason I do not think we can use constants in the way 
suggested. Then, Mr. Bylander suggested that a sum 
should be provided in the quantities to be paid to 
an inspector or clerk of works. If the builder has 
to pay the inspector or the clerk of works, then that 
inspector becomes a servant of the builder, and I 
think that method of payment undesirable. The 
inspector should be paid direct by the architect or the 
client. 

I am inclined to agree with a " good deal " of what 
Mr. Alban Scott has said as to the " specialist," 
although I do not go quite as far as he does. I think 
what we really come to is this, that the architect should 
learn a little about reinforced concrete (hear, hear). 
He should be able to design his floors, his beams, 
and his stanchions in such a way that he will be able 
to show on his drawings approximately the number 
of bars, their arrangement, and their diameter, the 
amount of reinforcement to take diagonal tension, and 
so on . The quantity surveyor is then able to measure 
it and put it into his bill. That would give the 
builder something to price, and form a basis upon 
which to measure extras and omissions. 

Turning to the question of measurement, Sir — this 
is getting to a part of the question which has not 
been discussed to-night — I think that the centering of 
floors should be dealt with in a little more detail 
than Mr. Theobald suggests. One case that occurs to 
me now is this : you have a square hall, such as 



466 THE CONCRETE INSTITUTE 

we are now sitting in ; in that hall you have a gallery 
going round, perhaps, three parts of the way ; you 
start at a certain level at one end, you have to rise 
all round, and as you work back into the angles you 
get all sorts of different curves, both in your floor 
slab and in your beam centering. A floor of that 
description, I think, should be kept apart, and not 
only described, but sketches and sections showing the 
various sweeps and bends should be added to the bills 
of quantities. 

Just one word more, Sir, and that is this : I think 
the steel which we get in helical or other curved 
reinforcements should be kept separate from the 
straight. Air. Theobald does not suggest that, but 
I think it should be done, and in dealing with helical 
reinforcement the diameters of the columns should 
be given . For instance, you would have so many 
hundredweights of steel of a certain diameter wound 
round the vertical bars, stating the number in a column 
of such and such a diameter, or so many hundred- 
weights round so many bars of a column of some other 
diameter. I think we are very much indebted to 
Air. Theobald for having brought the matter before us. 

MR. R. M. KEARNS, F.S.I. : Mr. President and 
gentlemen, I feel, like a previous speaker, that much 
that I had intended to 'say has already been anticipated . 
I shall fall back upon a few notes to see what remains 
to be said. I quite agree with Mr. Theobald in 
advocating that quantity surveyors should prepare the 
bills of quantities for reinforced work, but it seems 
to be generally understood that the specialist firms 
insist on the use of quantities prepared by their 
own experts. This is not a satisfactory state of 
things, as it is doubtful whether such quantities 
represent the exact amount of materials, more espe- 
cially as to the reinforcement, actually put into the 
building — apart, of course, from the question of extras 
or omissions — as the detailed drawings are only forth- 
coming as the work proceeds. The client is, therefore, 
in a position somewhat similar to that of the man who 
buys " a pig in a poke." Moreover, it is highly 
probable that the client would obtain closer and more 
favourable estimates from contractors if they were 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 467 

supplied with bills of quantities which would give 
them a reasonably accurate idea of the work required 
to be done under the terms of the contract . 

The matter is one of deep interest to quantity sur- 
veyors, for it is evident that the employment of rein- 
forced concrete is rapidly increasing. Note, for 
instance, the important building, his Majesty's new 
Stationery Office, now being erected in Stamford 
Street. We may see on that site a lofty mass of steel 
gantries ; we may watch the travelling cranes moving 
smartly backwards and forwards in response to the 
mysterious and silent power of electricity, and, like 
the man in the street, be lost in wonder and admiration. 
All this machinery, poised in mid-air on tall, slender 
supports, suggests, indeed, the vision of a " baseless 
fabric " which, as Shakespeare expressed it, will 
dissolve and " leave not a rack behind." In this 
case, however, it will leave a spacious and substantial 
building resting on reinforced foundations — a building 
which will no doubt be closely studied by prospective 
builders of warehouses and structures of a similar 
type. 

With reference to the items proposed to be inserted 
in bills of quantities, I regret that I cannot agree 
with Mr. Theobald on every point. My idea — and I 
am not unsupported — is that labour items should be 
discarded as much as possible. They are likely to be 
over-priced, so far as the centering is concerned, the 
latter, to a large extent, being only chargeable as 
" use and waste." It is not customary to measure 
the labours on centering in connection with the stone- 
work in Gothic window and door openings. Why 
start a new system ? 

Briefly, I would suggest that all the concrete walls 
and floors should be supered, keeping each floor 
separate. We are not likely to get, in the near future, 
any walls or floors exceeding nine inches in thickness. 
The concrete in beams and piers might be cubed. 

The centering to walls and floors should be measured 
over all surfaces and billed at per square or foot super. 
Door and window openings to be treated as suggested 
by Mr. Theobald. The casing to beams and piers, 
cornices, jambs, etc., might, with advantage, be 
measured at per foot run, stating the girth and giving 



468 THE CONCRETE INSTITUTE 

a figured section in the margin of the bill showing any 
angle fillets or splay cutting. 

The different heights from floor to ceiling and 
from floor to soffit of beams should be stated at the 
proper place. This is of great importance to builders 
when tendering. 

With reference to the reinforcement itself, I would 
suggest that the whole of the steel bars, loops, stirrups, 
or ties should be weighted and billed at per hundred- 
weight. There should be no numbered items. One 
might as well attempt to number the nails when 
measuring carpenters' work as to number the labour 
items in reinforcements. When wire is used for bind- 
ing it need not be measured, but should be mentioned, 
like the forging and bending of bars, in the general 
description. In short, the price quoted per hundred- 
weight for the reinforcement should cover the whole 
of the smiths' materials and labour. Where there are 
many beams, the reinforcement for which can be put 
together in the smiths' shop on the site, the fact should 
be stated. 

It should be borne in mind that bills of quantities 
are only the means to an end — namely, the sum for 
which a contractor will undertake to do certain work. 
It is an advantage to all parties if the quantities are 
clear and explanatory, but they should not be too 
elaborate, and thus lead to difficulties and unnecessary 
expense in connection with the admeasurement of varia- 
tions. And in these days of feverish haste and rapidly 
changing requirements in most departments of life, 
variations in contracts are absolutely unavoidable. 

Mr. W. E. DAVIS, Member Quantity Surveyors' 
Association : — Mr. President, Mr. Theobald, and 
gentlemen, I think we ought to thank the last speaker 
for really dealing seriously with the measurements, 
however much we may disagree with his methods . The 
first speaker, Mr. Alban Scott, rather abused the 
quantity surveyors because they had allowed them- 
selves to get into the position they had ; but I think 
the unfortunate quantity surveyors had no opportunity 
of doing anything else. Foreign firms came over — 
it is well known that the earlier systems of reinforced 
concrete were brought over by foreign specialists — 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 469 

there was an air of mystery about them, and their 
work was looked upon as something quite beyond 
the ken of an ordinary architect ; and I think that 
that possibly accounts for it getting out of the hands 
of the quantity surveyors. 

Another question is — and I think that in this all 
quantity surveyors will agree with me — why on earth 
the poor unfortunate quantity surveyor should always 
be the one to suffer for delays. There seem to be 
two points ; there is the one from the time the client 
thinks about building, and then there is that at the 
end, being the time when he wants the work finished. 
The client hesitates and hangs about a bit, and (I 
suppose amongst quantity surveyors it should be 
whispered ) possibly the architect is not quite so expe- 
ditious as he might be. (Hear, hear.) And then we 
come to the' other end, the work has to be finished 
by a certain date, the builder cannot do it in less than 
a certain time, and so the quantity surveyor is between 
two solid walls, as it were, and has got to be squeezed 
in in that time, so that if anybody is to be left out 
it seems to me that the quantity surveyor is frequently 
the one to suffer. 

But I am sure if the building-owner could only be 
persuaded of the advantage it would be to employ a 
quantity surveyor, not only on the mere question of 
value but the trouble it would save, he would do so. 
How many building -owners say they have built once 
and they do not wish to do so again because of the 
trouble they have had, the litigation and trouble in 
finishing up, which would, I think, in nine cases out 
of ten have been avoided by the employment of a 
quantity surveyor. 

I think Mr. Theobald's suggestion for measuring 
would meet with everybody's approval. I have had 
to do some of this, and I have found that subdividing 
the steelwork in sizes and then keeping that in loops 
and the spiral work separate gave satisfaction. I 
asked the tenderers afterwards whether it met with 
their views — it was in the early days — and they said 
it gave them all they wanted. I have since continued 
the practice and have not had any question raised. 
But the contractor simply pooh-poohed the idea of 
numbering bends. 



4J0 THE CONCRETE INSTITUTE 

With regard to the centering, I certainly cannot 
agree with the last speaker, and I think most quantity- 
surveyors will agree also, that the cuttings should not 
be omitted. But there is one point that I have always 
had a difficulty about, and that is the re -use of center- 
ing. You get a warehouse with, perhaps, five or six 
floors ; now, it makes a very great difference in the 
cost of the centering as to the number of times it 
can be re-used on the same building without a large 
allowance for waste. If any suggestion could be made 
as to how that could be dealt with in a bill of quan- 
tities, I think it would be useful. I am sure we all, 
quantity surveyors especially, and if the truth were 
known, architects and engineers also, would thank Mr. 
Theobald for laying down some definite lines for 
measuring. I think the time of the reinforced con- 
crete " specialist." with his fancy systems, is going 
by. He is undoubtedly getting out of date. There 
are many systems now, and engineers and architects 
are beginning to understand the material, so that there 
is no need for the specialist. Consequently the 
quantity surveyor will have an opportunity in the 
future, when the work can be put to open com- 
petition, and not left in the hands of the few. I thank 
you, Mr. President, for the opportunity of speaking. 

Mr. GEORGE CORDEROY, Assoc. Inst. C.E., 
F.S.I., M.C.I. : — I thank you, Mr. President, for 
the opportunity of speaking and congratulating my 
friend Mr. Theobald on the paper. I did not come 
here intending to speak to-night, and I regret I have 
not heard Mr. Theobald read his paper, though I have 
looked through it since I have been in the room. I 
congratulate him all the more upon his courage in 
tackling the subject, because I personally drew back 
from the task. I have an infinite repugnance to write 
papers on quantity surveying. I find it sufficient to 
have to write the bill. 

The difficulty which is experienced in taking out 
quantities for reinforced concrete work really, I think, 
resolves itself into this, that the system of reinforce- 
ment to be pursued has so seldom been settled 
before the tenders have been invited. The prac- 
tice which has largely prevailed hitherto has been 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 471 

to invite estimates for various systems of reinforced 
concrete for the same building or for the same struc- 
ture. As I said once before in this room some months 
ago, the difficulty that has pursued both the quantity 
surveyor and persons tendering is that it is rather a 
war of systems, or has been hitherto rather a war 
of systems, than the laying down with definite 
knowledge by the architect or the engineer as the 
case may be of a system to be pursued. 

I have had to deal in the course of my practice 
rather extensively with reinforced concrete work in dif- 
ferent forms, monumental buildings, warehouses, jetties, 
and wharves, and in the present state of knowledge and 
in the present welter of systems it is not possible to 
lay down any absolute method of measurement. The 
method of measurement which would apply to a monu- 
mental town hall is entirely inapplicable to a ware- 
house, and the method of measurement which would 
apply to a jetty is rather different from either. What 
it really comes to is this, that the trained professional 
mind of the surveyor must be applied to the circum- 
stances before him, and he must produce a bill of 
quantities which will present in an ordered form the 
varieties of work which have to be done, having due 
regard to the methods of construction which will be 
employed in connection with the particular system 
which it is anticipated will be used. 

I have had also, Mr. President, quite recently to 
prepare a schedule of quantities or a schedule of prices 
which really consists of an approximate bill of quanti- 
ties with a view to subsequent measurement for the 
construction of a building in which the parties 
tendering were each to state their own system. 
There were 26 parties tendering, and I think there 
were more than 26 systems tendered for. I am not 
quite sure about that, but, at any rate, some of the 
parties tendering were very liberal in the number of 
systems which they suggested, and tendered for two 
or three. The building has not yet been carried out, 
and I am looking forward with great interest to the 
time when I have to measure under the system which 
will ultimately be selected. 

Now, the preparation of a schedule of that kind is 
merely a tour de force. It was required and insisted 



47 2 THE CONCRETE INSTITUTE 

on in that individual instance, and it does not resemble 
what my friend Mr. Cross or the writer of the paper 
would regard as a bill of quantities. It has to be 
something of an entirely different nature to what we 
ordinarily mean or a surveyor ordinarily means by a 
bill of quantities, which is an analysis of the com- 
ponent parts of a designed building. 

It is a surveyor's duty to prepare in ordered form 
the analysis and statement of a settled fact. Now, 
a building or a structure of any kind tenders for 
which are invited under those conditions does not 
coincide with that description, and I agree with one 
of the speakers who said that he thought that what 
was really wanted, and what was really needed, was a 
better apprehension on the part of those designing 
buildings and other structures of the nature and 
properties of reinforced concrete work and a better 
understanding of its design, and I believe the time 
is coming (in fact, I believe it is at hand i when 
engineers will design in reinforced concrete, as they 
have hitherto designed in iron, stone, and brick, and 
when architects may perhaps do the same. 

I, personally, am not very sanguine of the exten- 
sive application of reinforced concrete to domestic 
or civic architecture. I would remind gentlemen 
here present that very distinguished men had a 
try thirty or forty years ago at concrete building. 
There is one in the Broadway now, one of the 
most dreary and miserable-looking buildings I know, 
but designed by one of the most distinguished 
architects of that day. 

Mr. W. R. HOOD, F.S.I., Past President Quantity 
Surveyors' Association : — Mr. Chairman and gentle- 
men. I scarcely expected to be called to speak upon 
this subject until the adjourned meeting, but as you 
have called me I do so with pleasure. The sub- 
ject is one which interests us as quantity sur- 
veyors particularly, and in so far as we are discussing 
it this evening, as to whether we, as quantity surveyors, 
should prepare the quantities for the general con- 
tractor rather than that the specialist should do it 
for us, we may in the near future have that question 
settled for us whether we wish it or not by an outside 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 473 

agency, and that is by the public authorities for whom 
we work. I speak from personal experience, and I 
have no doubt it is the experience of many others in 
this room also, that the detailed quantities have to 
be taken out for special work, for which, up to recent 
times, provisional sums have been put into the bills 
of quantities. I think we should certainly welcome 
that, although up to the present it has involved rather 
less labour than will fall to our lot in the future ; 
and, I think, in reinforced concrete work we shall have 
to do the same as we have done hitherto with con- 
structional ironwork. 

The remarks of Mr. Alban Scott were very inter- 
esting, and some of his utterances struck very hard, 
and no doubt reached the target in a great many 
cases, and in some cases probably fell short ; but, 
at the same time, I think they have given most of us 
material for thought. 

The subject of the paper that Mr. Theobald has 
read will certainly lead to considerable discussion in 
the future in another place — in fact, in two places ; 
for I certainly consider that the Council of the 
Surveyors' Institution should feel it incumbent upon 
it to call a meeting of its own members and the 
Quantity Surveyors' Association, and, with the assist- 
ance of the reinforced concrete specialists, to formulate 
a system of measurements which will be generally 
adopted. I think the sooner that is done the 
better, since, no doubt, there are a great number 
of different ways of measuring reinforced con- 
crete work. There is great probability that, if all the 
quantity surveyors in this room had the same set of 
drawings and specifications from which to measure, 
they would produce bills of quantities that would differ 
very considerably, although possibly, in the end, the 
general contractor would be able to price them equally 
well. But if we could standardise the system of 
measurement, I think it would be to the advantage 
both of the building -owner, the quantity surveyor, and 
of the general contractor. 

I think, also, that the employment of a quantity 
surveyor in this matter would be of considerable 
advantage to the building-owner, who, of course, is 
the first person to consider. 



474 THE CONCRETE INSTITUTE 

There is undoubtedly an element of speculation in 
the present system, although a speculation with only 
one side to it, I am afraid, is scarcely a speculation ; 
but still, there is only one side to it, for the reason 
that if a " specialist " is invited to give an esti- 
mate for a particular system of reinforced concrete 
work he naturally takes out the quantities in such 
a way as to cover himself for any contingencies 
that may take place, and therefore the estimate which 
he produces is probably not an accurate estimate of 
the work which has to be carried out. Another subject 
was referred to by Mr. Theobald — viz., variations in 
the general drawings and the detailed drawings after 
the quantities have been prepared by the " specialist " ; 
those are the words, I believe, of the paper ; naturally, 
variations should be adjusted, either before the esti- 
mate is accepted or at the completion of the contract ; 
and if he does not adjust those variations, who is going 
to get the benefit of it ? Undoubtedly, the reinforced 
concrete specialist, not the building-owner. With regard 
to the point Mr. Theobald mentioned in his paper where 
he met another surveyor, and they endeavoured to get 
the original measurements from the " specialist," and 
that gentleman gave him a few figures of totals, 
Mr. Theobald says he would not tell, and naturally 
he would not tell, who got the benefit of that trans- 
action ; but I can make a very shrewd guess, and I 
think most of us could do so ; there is no doubt but 
that the building-owner was not the man who got the 
benefit, so that the easier access we have to the original 
dimensions the better for all purposes ; and I think 
that the sooner the members of the Surveyors' Institu- 
tion meet — and I hope that Mr. Corderoy, whom I 
see present (being a member of the Council of the 
Surveyors' Institution), will do his best to bring 
about this meeting of those particularly interested 
in the subject, and get a standard method of 
measurement agreed — the better we shall all be 
satisfied. 

THE PRESIDENT (Mr. E. P. WELLS, J.P.):- 
There are a great many more wishing to speak on 
this subject, and as at the next meeting, on Decem- 
ber 1 2th, we shall be short of one of the papers, I 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 475 

propose to adjourn this meeting, to then continue 
the discussion, and also to listen to a paper by Mr. 
Laurence Gadd, F.I.C., on " The Effects on Concrete 
of Acids, Oils, and Fats." 

But before we adjourn I should like to say a few 
words, as there are so many quantity surveyors present, 
just to give you an inkling as to how to proceed by 
way of coming to a common agreement on taking 
out quantities for reinforced concrete work. And when 
you are all, I hope, here on the 1 2th of next month, 
there will be something more to talk about, and I think 
we may look forward to a fairly healthy discussion. 

I will now show you the method I have adopted 
for several years in taking out quantities, and as a 
rule you can take the original quantities, if they are 
asked for at any time, and you can check every 
measurement from start to finish. For example, a 
building is to be put up ; it does not matter whether 
it is an ordinary building or an engineering work, or 
what the nature is. Take, for instance, one thing only 
— a column, and we will assume, for the sake of 
argument, that we are dealing there with the base 
inclined at an angle of 45 degrees. In taking out 
quantities, this is the method I adopt : I have paper 
that is specially ruled divided up in columns as follows 
[illustrating on blackboard ], and you will now see the 
simplicity of the method. We will just say, for the 
sake of argument, that this first column represents 
concrete, the next represents shuttering, the third 
represents steel, the fourth represents the abstract or 
the analysis, this is the rate column, and the last is 
the total in pounds, shillings, and pence ; so what we 
have is. this — every detail of the quantities from start 
to finish, the whole analysis, the rate of the bill, all 
staring you in the face in one operation. It is not 
.a case here of taking out quantities all over the place, 
then starting afterwards and abstracting them, and 
that is where so many mistakes are made. 

Now, for instance, we will take out the first item — 
concrete. We will give its area by its thickness and 
reduce it down to cubic feet. We come along to the 
next column — the measurement for shuttering [illus- 
trating I . Now, if the angle is 33 degrees, shuttering 
for that base is not required, as the concrete will 



476 THE CONCRETE INSTITUTE 

stand up, but if it is to be 45 degrees the con- 
crete will not stand up ; therefore it becomes necessary 
to put a subheading under " shuttering," for the 
simple reason that the extra cost of making the shutter- 
ing on the splay is caused by the cutting of the angles 
and the holding of the whole together. 

We pass next to the steel column, and the whole of 
the steel is shown — sizes of bars, their lengths, their 
weights, and also the shear members. This gives 
us the weight of the steel in the base. 

Now, this finishes the base of the column, with 
everything taken out — its concrete, its steel, its 
shuttering, both plain and splayed. You then carry 
the totals into the abstract column, also if there are 
any labours ; but, as a rule, in column bases they are 
absent. When you take out your proper bill of quan- 
tities, you have everything here for your abstract, 
not having to go back to, say, sheet 22, or any back 
references being necessary. 

We will now take the column shaft ; the same 
method applies . You first take the concrete, then the 
plain shuttering, the splayed shuttering under a 
separate heading : then take the steel in plain rods 
and any hooping or linking under separate headings, 
all of which is abstracted in the fourth column, as well 
as any extra in labour, etc. 

Now, the same method applies in all descriptions 
of works. If by any possible chance there is any 
.circular work, it is taken as an extra per foot super 
on the ordinary work. When it comes to windows, 
I always make the deductions for the window area, and 
I state in the quantities that everything is net, not- 
withstanding any trade custom to the contrary. Now, 
this system is followed out in its entirety from start 
to finish ; reinforced concrete quantities are the easiest 
to take out of any work that I know. I am speaking 
now with an experience of over forty years since I 
first started taking out quantities ; then it was in 
wrought -iron work ; steel was not known. I have 
gone through the whole gamut up to the stage of 
reinforced concrete, and I say this : there are no quan- 
tities so easy to take out as reinforced concrete work, 
if you go on a system, and you must have a regular 
system to do it. 



TWENTY-EIGHTH MEETING, Nov. 28, 1912 477 

But I should recommend that all quantity surveyors 
should depart from their usual method of taking out 
quantities for this work. When concrete is given, 
it is far better to do it in cubic feet, except you have 
got mass concrete, than in cubic yards. If you have 
ordinary shuttering, you give it in square yards ; if 
it is special work, let it go into square feet. You 
keep your splayed shuttering all separate from your 
ordinary, because, as a rule, the value of this is three 
to four times the value of ordinary straight shutter- 
ing — that is to say, that if you take a floor shuttering, 
as compared with a column shuttering, the value of 
the latter is nearly twice as much. 

It is the same thing as regards external and internal 
shuttering in hopper bottoms for silos. I have seen 
the foolish builder putting the price down at is. per 
square yard, including all his profits, and he was not 
content with that, but took his internal at 9d. When 
all the information is given to a builder and he puts 
down prices like these, he has only himself to blame 
for any mistake he makes, and then the subsequent 
loss of money. I have known a builder quote for 
hopper shuttering at 2s. 6d. per square yard, when 
I know that every square yard he put in cost him 
7s. 6d. The reason why these mistakes are made so 
constantly is this, that very few people understand how 
to price the costs in their tender of the labours, and 
their relation to the strutting, and reduce that down 
to a super-measure. When once they have learned 
to base the prime costs, starting from iron ore as an 
example, then work it right up to the pig, then cost 
of manufacturing, etc. — when, I say, they have learned 
that thoroughly they will not make the mistakes they 
do at the present day. 

In adjourning the meeting, I have just a few words 
more to say. If anybody at the next meeting has any 
suggestions to offer, by which they can simplify the 
taking out of quantities, I should be glad if they 
will do so. And what I also recommend is this — that 
beams, columns, and floors be kept all separate from 
the foundation upwards : separate them all through, 
so that when the time comes to measure up there will 
be no difficulty whatever in following the working, and 
a child, even the office-boy, can follow the work. 

11 



47» THE CONCRETE INSTITUTE 

Another thing I should recommend is this, that when 
the bills of quantities are got out, instead of putting. 
as is general, in the left-hand column of the quan- 
tities the superficies, etc., I should give the number 
of the item, and at the end of the description the 
yards cube or feet cube, etc., as the case may be, so 
that if at any moment a question arises, What do you 
mean by item 190? you can give it, and you do not 
need to turn to page 54, tenth line, etc. It is a rapid 
means of getting to work ; it simplifies everything, 
and that is, I think, what Mr. Theobald would wish. 
And if you, as quantity surveyors, would do likewise — 
that is, take out quantities in such a manner, then 
any one can follow them ; any other quantity sur- 
veyor can take them up and, getting hold of the work- 
ing drawings, can follow them up from start to finish. 

The discussion is adjourned till Thursday, Decem- 
ber 1 2th, at 7.30 p.m. 



TWENTY-NINTH ORDINARY GENERAL 
MEETING 

Thursday, December 12, 191 2 

THE TWENTY-NINTH ORDINARY GENERAL 
MEETING of the CONCRETE INSTITUTE was held 
in the Lecture Hall at Denison House, 296 Yauxhall 
Bridge Road, Victoria, S.W., on Thursday, Decem- 
ber 12, 1912, at 7.30 p.m. 

Mr. E. P. WELLS, J. P., President, in the Chair. 

THE PRESIDENT (Mr. E. P. Wells) —Gentle- 
men, the first business we have before us this evening 
is the applications for membership. They have 
already been before the Council and approved, and 
I will put the several names to you, and unless I hear 
to the contrary I will assume you agree to their being 
elected : — 

1. Mr. Wilfrid Lawson Carter, B.Sc, M.S. A., 
Southend -on -Sea . 

2. Mr. Richard Collins, M.I.Mun. and C.E., 
Engineer and Surveyor to Enfield Urban District 
Council, Enfield, Middlesex. 

t,. Mr. Charles Heaton Fitzwilliam Comyn, 
A.R.I.B.A., M.R.San. In., London, E.C. 

4. Mr. John Theodore Gilbert, Surveyor, 
London, W. 

5. Mr\ William Whittaker Goulding, P.A.S., 
Manchester. 

6. Mr. Edwin Palser, Licentiate R.I.B.A., 
London, W. 

7. Mr. John Parham, Mem. R.San. I., Enfield, 
Middlesex. 

8. Mr. Arthur James Pitman, London. S.W- 



4 So THE CONCRETE INSTITUTE 

9. Mr. Robert Orr, A.R.I.B.A., P.A.S.I., 
London, E.C. 

10. Mr. James Enos Streadwick, Kingston, 
Jamaica . 

11. Mr. Rudolph Nielsen Stroyer, M.Inst. 
C .E . (Denmark), B .Sc .Eng . (Copenhagen University), 
London, S.E. 

12. Mr. William F. Laurie Thomas, Demerara, 
British Guiana. 

13. Mr. J. Mason Blair, M.I.C.E., Engineer -in - 
Chief, Otago Harbour Board, Dunedin, New Zealand. 

There are also two applications for studentship — 
namely : — 

1. Mr. Charles Guy Burke Burdett, Mem. 
Junior Inst. Engineers, Westminster, S.W. 

2. Mr. Walter Frederick Slate, Westminster, 
S.W. 

This brings the total number of members up to 947. 



CONTINUED DISCUSSION ON MR, 
THEOBALD'S PAPER 

THE PRESIDENT (Mr. E. P. Wells) :— After 
I had adjourned the discussion on the paper on " Bills 
of Quantities for Reinforced Concrete Work," I was 
spoken to by one or two quantity surveyors as to 
the method that I employed in taking out quantities 
for reinforced concrete work, and whether I would 
also prepare a cartoon for this meeting. As you will 
see on the cartoons, I have given you a general out- 
line of the methods that I employ throughout in 
taking out quantities for reinforced concrete. 

These cartoons represent the sheets that go out to a 
contractor when he applies to me to get out designs and 
quantities for the work. You will see they are divided 
into four columns. Now, if it is a question of pre- 
paring proper bills of quantities in the usual way, 
the last column can be used for all labours, etc. 

[The President then entered into the methods he 
employed in taking out the quantities in detail, and 
transferring the same to the paper, as shown by the 
cartoons. ] 

In conclusion, I strongly recommend that all items 









■d ° 


t^ 


o 




o 


X 


* 


-t- 


". 


o 


c 








. C> 


_ 


f^ 




r- 


i/". 


CI 


H 


sc 


ci 


N f, 








X — • 
















w 












~!° 


o 


o 




o 











C 


e ; 






j 


■d o 


o 


o 




-^ 


r ^. 


»c 


c^ 


M 


ci 


o 






— 




























K 


B H 


M 


m 




o 


M 


CI 


o 


o 


O 


c 
































< 




« 


r5 


rt 














































en 


CU 
























■* 




CO 


























j>i 










■d 


[II 
















e 










**-> 


s 








* 






?, 


< 


< 

a 
■r. 

< 








r. 


CO 








w 






^w 






, : 




n'r 






'— ' 




SOW 






— 






'— 


•c 


ri 






- 




rt 




,_• 


i. 




PQ 




.Q 


>^ 


£ 






a 


-^ 


S^ 




— 


,2 








O 

•J 


b" 

■f. 
00 


a, 

CO 

2 




On 


o 

o 
ri 

u 


^> 


CO 


t>. 


X 


_l 








"P 








ri 


i> 


















u 


U 








■J 


u 














\j 










D 


























:j 








CJ 




















u 








u 












z 


J3 














V 








U 


CO 


CO 




55 


O 


CO 


CO 


CO 


CO 


-i. 






,_ 


t> 1 








1^ 


1 




'"• 1 












- 


1 1 








c 


1 




" 1 


■/. 








•14 




-t- 






fH 






50 


t^ 


2 


J 




"55 


'J-j 




o 








jd 












u 
7. 


< 

PQ 




b 






< 


1^ 




z 


b 


5 


-51 








rt 






-.o 


- 1 




M 


R 


w 


-i- 


















"* 






^ 


fZn 








































o 








-: 






r| 










































^+ 








CI 
















































"o* 














-t" 














H 








-T 






ci 












_ 


1 




N|0 


1 










r:^ 


„_ 










\»1 




O W 


1 


O 
X 


o 


1 


CI 


M 


r ^- 




































X 


~ 




^ 




















< 
pq 




o 

X 


-J 
CO 


"ci 
X 


CO 


"ri 
X 




X 


Hci 

-T 

X 


X 














O 




„ 






2 


O 




















O 




















_^ 




^ 




N 






-^1 


d. 












■* 




-T 




"5= 






N 


CI 










a 


30 il 




-1 




° 1 






HCT 


1 












I 




- 1 




N 1 














































•j 
























u 
"cu 
o 


a" 

■r. 






< 


M 


— 


ci 




i 


-CI 

-r 








s 

O 


PQ 




o 

X 

%*■ 

X 


CO 


X 

HS 
X 

~-t- 

X 


CO 


X 
X 

"6 




X 


X 

c 

X 

£ 
CI 












482 



THE COXCRETE INSTITUTE 




£' 4 : 6'i 



Fig. 1. 




Fig. 2. 



Vfl ^t- H _, _, 



S3 



is -a 



O Z> - 



— ' 










"^ 
















g 










cr 






















V 




Cfl 

-t- 
ci 

5 

re 




d 


3" 














o 


Cfl 


^£ 


is. 




o 


t/: 


p 




































u 


CN 


o 

-t- 


2 




u 


CO 















V 




<N 


eg 




"d 


















o 










<u 














■-) 


3 


"3 







G 


^5 




3 










z 


i 


O 


~ 











o 










U 


55 


35 


" 




o 


X 


en 










si 


o 


i 










o 


1 






. 


, 




M 
«lo 


1 










N 


1 






- 






re .' 




















u 






oj ty 




















X 






re *; 
"d ~z 

G fH 












O 

"re 






•c 








s 






>~, 


















o 
U 






dr 

en 






"pi 






& 


























-la 








CO 


ir. 


1 * 1 


- ' '1 






X 




X 1 


CO 








GC 




1 * ! 


ri 1 






cs 




ts 




1 


< 


& 

CO 






3 


II 




6* 

CO 






5 
































c/3 




„ 






















v 




CO 














































Jj 


o 




X 








§ 


























< 












- 


-j 




"o **> 








w 




; 








7. 

i 


X 

'J 
z 




x' 


"i<") 

X 

CO 






ffi 




O 
X 












si 


o 
o 


|| 


•d 


ft l| 




« 


o 


! 










s 












x 




















er 






3 














C 


in • 




v: 


re 
u 




o 










J 






X 






CJ 






^ 








•J 






o, : 






"S 






c 








C 



o 






2 « 

x x 

o 






u 


o 

d 

B 
re 
u 

o 






X 
X 









484 THE CONCRETE INSTITUTE 

in a bill of quantities should be numbered for easy 
reference, starting at 1, and so on to the end of the 
bill. It is far easier to refer to a number than to a 
certain line on a given page, and if alterations are 
required, it is quicker to say, "Alter item 150 to 
50 cubic yards " than the usual long references. 

Mr. R. W. VAWDREY, B.A., Assoc. M. Inst. C.E. 
(Member of Council) : — I greatly regret not having 
been present to hear this paper read. I am con- 
nected with a specialist firm, and I must say, as far 
as I am concerned, I entirely agree with every single 
word that Mr. Theobald has said in his paper. The 
whole position of the question of designing reinforced 
concrete work in competition, as it exists at present, 
is most unsatisfactory, and to a very great extent 
I think that is due to the absence of the regularized 
method of dealing with the matter that obtains in 
nearly all other classes of construction. 

But there are just a few points which Mr. Theobald 
makes in his paper that I should like to refer to in 
detail. To start with : he says on page 437 that when 
an architect decides to construct a building in rein- 
forced concrete, he sends out sets of plans, etc., to 
one or more firms of specialists. If he confines him- 
self to one firm of specialists, I do not think any of 
the ■ unsatisfactory difficulties arise. The great diffi- 
culty, and the great amount of dissatisfaction which 
occurs in connection with the design of reinforced 
concrete work, is owing, in my opinion, to the fact 
that contractors are asked to tender, not upon one set 
of designs or one set of quantities, but on many such 
designs, all differing from each other. You get Jones 
and Smith tendering on one set of quantities and 
designs, and you get Brown and Robinson tendering 
on others, and so forth. It is that which introduces 
the chief difficulties that exist in the present system. 

Mr. Theobald states, lower down on the same page, 
that the question of time tends to prevent the proper 
production of the quantities by a quantity surveyor, 
but surely that is an altogether inadequate reason. 
As he points out, no more time is required in the case 
of a reinforced concrete structure than in the case, say, 
of a steel structure, and therefore no more difficulty 
can occur in having the quantities properly prepared. 



TWENTY-NINTH MEETING, Dec. 12, 1912 485 

I am quite sure that everybody who has had any 
experience of the question will agree with Mr. Theobald 
that the specialists concerned — that is, those firms who 
make it their business to design in reinforced concrete 
— will welcome with open arms the introduction of the 
quantity surveyor, and I should like to point out that 
perhaps it is not quite so unusual a thing as Mr. 
Theobald thinks. In our own case, it is very fre- 
quently the case that our designs are submitted by 
the client for whom we have prepared them, either in 
competition or not, to a quantity surveyor for the 
proper quantities to be taken off. I do not think any 
of the concrete specialists have any objection what- 
ever to that procedure. As is pointed out in the paper, 
that merely relieves them of a great deal of elaborate 
work for which they are not so well fitted as a quantity 
surveyor, and, of course, it relieves them also of some 
responsibility. 

The point that Mr. Theobald makes on page 445, 
that he asks for a separation order, is, I think, a very 
good one. And this has been elaborated, of course, 
by the President in his remarks just now. The more 
the quantities for the different portions of the struc- 
ture — the footings, columns, beams, etc. — are separated, 
the clearer and the cheaper it undoubtedly is ; in my 
experience, at any rate, I have found throughout that 
the greater the detail in which the quantities are 
given, the cheaper will be the prices obtained by the 
owner of the building. 

I should like to go farther, and say that the separa- 
tion of the quantities alone is not sufficient. The 
great point, in my opinion, as I tried to point out in 
a paper I read here on a somewhat similar subject a 
year or two ago, is that the question of the design 
and competitive tenders should be separate. It appears 
to me most disastrous that for some unknown reason 
the practice has become such as it is at present — 
namely, that the competitive designs which are neces- 
sary perhaps in some cases and competitive tenders 
which are more generally necessary should be merged 
together in one tender. 

Then to deal with the discussion. The letter from 
Sir Henry Tanner merely bears out that point which I 
have just made. I naturally entirely agree with what 



4 86 THE CONCRETE INSTITUTE 

he says. On the question of delay he says a great 
delay occurs now, owing to the fact that after merely 
preliminary designs have been prepared, a tender will 
be accepted on them, and then subsequently before 
the work can be commenced all the detailed working 
drawings have to be prepared. Of course, they ought 
obviously to be prepared before the tender is accepted. 
That can only be done if a design is accepted, or a 
particular firm of designers is appointed before the 
work goes to tender. 

I will just refer to one or two points made by Mr. 
Alban Scott. Of course, I entirely agree with his 
remark that it is unfair to the contractor if the various 
sizes of steel rods are not separated and specified. 
Clearly they should be, and of course they would be if 
a proper bill of quantities were taken out from the 
specialist's designs. 

.Mr. Alban Scott says that an architect is employed 
to look after his client's interests ; he cannot do this 
if he throws the responsibility of a portion of the 
work on to some other person . One would hardly 
suppose from that that Mr. Alban Scott had ever 
employed a specialist for his reinforced concrete work, 
yet I believe such to be the case. 

Again. Mr. Alban Scott says that specialists do not 
guarantee their quantities. Of course, it may be the 
case that sometimes they do not ; on the other hand, 
sometimes they do, and it is surely very unfair to cast 
mud at random in that way. He says that " they do 
not as a rule employ men who have had training 
as quantity surveyors." Surely a firm of specialists 
may employ quantity surveyors as their assistants. 

In conclusion, I should just like to call attention once 
more to the unsatisfactory nature of the present condi- 
tions. I think we all admit that the present method 
of tendering for reinforced concrete work is very un- 
satisfactory. The reason, as I have already said, is, in 
my opinion, the confusion of the question of designing 
in competition with that of tendering in competition. 
But I do wish to say that it is not the specialist firms 
who are to blame in the matter. If all architects would 
only realize that these firms exist as specialist firms 
of designers for the purpose of designing, things would 
be very much simplified. At present, in the great 



TWENTY-NINTH MEETING, Dec. 12, 1912 487 

majority of cases, architects or quantity surveyors 
acting for their clients almost invariably ask the 
specialist firms to submit tenders. Well, of course, 
that is absolutely incorrect. The specialist firm does 
not, except in a very, very few instances to my know- 
ledge, submit tenders. The specialist firm is a iirm 
whose existence is for the purpose of designing rein- 
forced concrete work. If an architect wishes to erect 
a reinforced concrete structure, if it is essential for 
him to have competition, which I think it very seldom 
is, let him go to two or three firms, ask them to show 
what they can do, and to submit designs to him for 
his approval. Then let him accept the best, and 
let him submit that design which can then be worked 
out in full detail, to any number of contractors. 

Let as many as he likes tender on the same design, 
but for goodness' sake let the architect get out of the 
habit of asking half a dozen specialist firms, or, more 
usually, all the specialist firms he can get hold of, to 
submit tenders. That means that specialist firms pre- 
pare the design themselves, ask the half-dozen or 
more contractors to tender upon it, and get the product 
of the number of specialists, and the large number of 
contractors as the total number of tenders sent in. 
The whole thing is, of course, absurd. Very often no 
one contractor is tendering on all the designs, and 
the best design is probably not tendered upon by 
the cheapest contractor. Consequently, so far from 
increasing the economy of the work, the owner of 
the building probably has to spend a great deal more 
than he otherwise would have done. 

MR. FREDERIC HINGSTON, M. Quantity Sur- 
veyors' Assn., M.C.I. : — Mr. President and gentlemen, 
I am much obliged to you, sir, for asking me to join in 
this discussion, and also for the very clear statement you 
have given us of your suggestion for taking out quanti- 
ties for reinforced concrete work. There are one or two 
points which I should like to mention, more with regard 
to the taking out of quantities for reinforced concrete 
work than for the employment of the specialist. I 
quite agree with some of the remarks of the last 
speaker, more especially with regard to employing 
one system and one firm for the work. But I am 
more concerned with the quantities than with the 



488 THE CONCRETE INSTITUTE 

specialist, and with regard to the concrete work itself, 
I think I understood Mr. Theobald to say that the 
concrete to the walls and the floors should be kept 
separate and the columns separate from either or 
both of the preceding. With this I agree, but I do 
not agree with the suggestion that the labours on 
small rods should be taken, unless the labours are 
very numerous . 

As regards the centering, that should of course be 
taken at per square. I think that the beams should 
be given at per foot run, giving the sizes where 
possible. Of course, where the sizes differ very con- 
siderably they might be averaged, and I think those of 
one width might be averaged in the depth, and those 
of one depth might be averaged in the width. Shutter- 
ing to the beams should include the triangular fillets, 
and any labours upon them, and the labours to the 
superficial items taken separately. I also agree with 
him when he states that the openings in the shuttering 
to walls and floors should be deducted, and the extra 
labour for forming the openings should be numbered. 
As regards the larger steel work I think the labours 
thereon should be taken, and I agree with the last 
speaker that the whole of the steel work should be 
kept separate under its different sizes and the labours 
described. 

There was one point I notice Mr. Theobald did not 
mention, and that was the finishing of the concrete. 
I take it that he would take that separately, and treat 
it very much as we do the plastering or similar finish- 
ing on the inside, and whatever facing there is on the 
outside, and whether of stone or brick should be 
described as facing to reinforced concrete work. 
Perhaps when you reply you will mention these points. 

Mr. G. C. WORKMAN, M.S.E. (Member of 
Council i : — Mr. President and gentlemen, I very much 
regret that owing to illness I was not able to attend 
the interesting paper read by Mr. Theobald. I have 
carefully considered his views concerning this im- 
portant question, and. speaking from the point of view 
of an engineering designer working under a patented 
system, I venture to make the following remarks : — 

First of all, I am very pleased to see that Mr. 



TWENTY-NINTH MEETING, Dec. 12, 1912 489 

Theobald states quite clearly that he is making no 
reflection upon the quantities supplied by the engineers 
under the present system, and that his criticism is 
solely directed against the actual method of dealing 
with reinforced concrete work and not against its 
exponents. As a matter of fact, the reinforced con- 
crete engineers are directed by circumstances over 
which they have very little control, and I feel perfectly 
sure that in many cases they would welcome the help 
of a quantity surveyor. Perhaps Mr. Theobald will 
be astonished to hear that I personally have endea- 
voured for many years to bring about a collaboration 
between the reinforced concrete designer, the archi- 
tect, and the surveyor. Unfortunately, as mentioned 
before, we reinforced concrete designers are depend- 
ant upon the requirements of our clients, and com- 
petition prevents each individual firm of designers from 
attempting to dictate the proper course which the client 
ought to follow for the mutual benefit of all concerned. 
For instance, Mr. Theobald says that he is well aware 
that the time given for the preparation of a scheme 
and quantities does not admit of the employment of 
a quantity surveyor, and he suggests that the client 
must wait. The difficulty is that the client will not 
wait. The conclusion is obvious. 

Mr. Theobald states that he believes that under the 
present regime the correctness of the quantities is 
not guaranteed. As a matter of fact, most of the firms 
of reinforced concrete designers working on similar 
lines to ours — I am now referring to the Coignet system 
— must guarantee the accuracy of the quantities, or 
at least of the unit quantities of concrete, steel, and 
centering for each element of the construction. It is 
evident that under these circumstances, taking into 
account the fact that the work must be done in many 
cases with extraordinary rapidity, there is a consider- 
able amount of risk. The point is, assuming that 
surveyors would be willing to take out the quantities 
very rapidly of a large number of competitive schemes 
throughout the year, would they be prepared to take 
the financial responsibility for the accuracy of their 
quantities, and also to do this on the understanding that 
they would not receive any remuneration whatever for 
all those schemes which the firm of designers in col- 



490 THE CO X CRETE INSTITUTE 

laboration with whom they were working were not 
successful in securing ? 

I am strongly of opinion that before anything prac- 
tical can be done in the direction suggested by Mr. 
Theobald it will first be necessary that quantity sur- 
veyors should make an exhaustive study of the various 
systems which are at present continually in competi- 
tion for works in reinforced concrete, and also that 
they should solve the question as to whether or not 
they are prepared to work in collaboration with the 
designers on the same speculative terms as the latter 
are compelled to adopt on account of the fact that they 
see no other alternative. 

Mr. Theobald states that the methods of the modern 
quantity surveyors are the outcome of the knowledge 
of three or four generations who have had constant 
practice in this profession. Unfortunately, the quan- 
tities for reinforced concrete are quite different from 
anything to which surveyors are accustomed, so that 
the experience of all their ancestors will be of very 
little avail to them. In fact, I will go farther than 
this, and I would make so bold as to state positively 
that unless a quantity surveyor has a perfect knowledge 
of the particular system of reinforced concrete for 
which he has to take out quantities he is far less 
capable of doing this work properly and rapidly than 
the specialist engineer. 

In conclusion, I am of opinion that the entire ques- 
tion concerning the employment of quantity surveyors 
in conjunction with reinforced concrete chiefly depends 
on whether or not the quantity surveyors are willing 
to take the same responsibilities and run the same 
risks as the specialist engineer, and I may add that 
personally I am quite willing to discuss this question 
with any surveyors who may wish to get better 
acquainted either with the system of reinforced con- 
crete, which I represent, or concerning the subject in 
a general sense. 

Mr. MORITZ KAHN, M.C.I. :— Mr. President, I 
think Mr. Theobald has the honour of having pre- 
sented one of the most interesting papers that have 
been read before this Institute, and although a good 
many kind things have already been said of him. I 
want to put in my little word in thanking him as well. 



TWENTY-NINTH MEETING, Dec. i_\ 1912 491 

The paper under discussion only came before my 
attention this afternoon, and therefore I have not been 
able to give it that study which it merits, judging 
from the casual glance I cast over it. 

I quite agree with most of the remarks I have read 
in Mr. Theobald's paper, and, like Mr. Theobald, I, 
too, hope that sooner or later, rather sooner than later, 
the quantity surveyor will take an active part in the 
measurements of reinforced concrete work. We delight 
in the designing of this class of construction, and a con- 
siderable amount of our cares would be removed if a 
fully qualified quantity surveyor were engaged by the 
architect to prepare our quantities. 

I would call attention to the fact that the prepara- 
tion of quantities for reinforced concrete work is prob- 
ably more intricate than the preparation of other 
quantities. Each designer has his own method of 
detailing the work. These methods differ to a con- 
siderable extent, and standards which might be drawn 
up for one designer will not apply to another. The 
measuring of the concrete and steel in the respective 
items is a simple matter, and under ordinary circum- 
stances the measuring of centering is a simple matter, 
but the ordinary circumstance is not the rule, with the 
result that, speaking offhandedly, it is a difficult matter 
to generalize a method of measuring quantities of 
centering. It seems to me that satisfactory results 
can be obtained by giving the contractor general 
measurements of the centering and submitting with 
your measurements such drawings as will enable him 
to understand the nature of the work he will be called 
upon to perform. After carefully studying such 
drawings, his experience ought to teach him how to 
price the centering. It is unfair that I should take up 
too much of the time of the members of this Institute 
in discussing a paper which has not been previously 
carefully studied by me, but I could not resist the 
temptation to say a few words, because the subject is 
such an interesting one to me. 

Whilst I do not propose to submit a plea for the 
specialist, might I call the attention of the quantity 
surveyor to the fact that the present method adopted 
by the specialist is one which has been forced upon 
him by circumstances over which he has no control. 



49- 



THE CONCRETE INSTITUTE 



The specialist is not an enemy of the quantity surveyor. 
and, speaking for myself, I have often gone out of 
my way to insist upon a fully qualified quantity sur- 
veyor being called in to check either our original 
quantities or quantities of alterations in the final con- 
struction. I know for a fact that we specialists invite 
the assistance of the quantity surveyor whenever and 
wherever we can possibly find an opportunity to do so. 

Mr. PERCIVAL M. FRASER, A.R.I.B.A., M.C.I. : 
— Mr. President. I am in the position of one or two 
other speakers here ; I was not at the last meeting, 
and I do hope I shall not traverse the same ground 
that other speakers traversed at the last meeting and 
this evening. 

Coming straight to the paper, as a quantity sur- 
veyor I have to take exception to a few remarks that 
Mr. Theobald has made. I admire the style of his 
paper ; it is a kind of literature we seldom get at this 
Institute. It is very breezy and racy and a real 
pleasure to read, and, as the advertisers say, once 
picked up you cannot lay it down till you have 
finished it. 

On page 436 he says the apologia fox a quantity sur- 
veyor preparing bills of quantities is that he gives 
a client the right of criticism. He says this is what 
the client likes. But I do not think there is one client 
in a thousand ever sees the bills of quantities ; they 
are nasty-looking things for the layman. I do not 
think the client would peruse them with any great 
gratification, and I think Mr. Theobald might correct 
that impression, that the bills of quantities are simply 
to give the client that insight into the methods by 
which the building is carrieci out ; they are tor a much 
more serious use than that. 

He says : — 

'* At the present time, when an architect decides 
to construct a building of reinforced concrete, he 
sends a set of plans, sections, and elevations to 
one or possibly more firms of specialists, who 
then submit a scheme of construction under their 
respective systems, together with an approximate 
estimate of the cost." 



TWENTY-NINTH MEETING, Dec. 12, 1912 493 

Well, this is not the time to discuss "first principles, 
but he is quite wrong there, I think. He saddles an 
architect with this somewhat undesirable method of 
carrying out a concrete building. I think he might, 
in mercy, have included engineers. Architects, I think, 
do not adopt this method ; it is a very iniquitous one. 
The concrete specialists themselves are beginning, I 
think, to freely state that they think the spirit of 
competition is very iniquitous, and I feel quite certain 
that I am speaking the truth when I say that every 
day shows a falling off in the desire of architects to 
have their concrete schemes prepared in a spirit of 
competition. 

In regard to the specialist's approximate estimate, 
I do not think this is ever done. It may be done by 
special request, but surely it is not the common prac- 
tice that Mr. Theobald states it is. One might almost 
imagine, from what he says, that specialists draw up 
their own specifications, supervise the building, and 
draw their own cheques on their own bank themselves, 
but their sphere is much more limited than he evidently 
thinks. 

I must say that Mr. Theobald rather admits that he 
has little or no experience with regard to reinforced 
concrete buildings, and he seems to propound a large 
number of conundrums. I presume that we are invited 
to reply as far as possible to those questions. 

With regard to the quantities supplied by specialists, 
this is absolutely universal, and I have never noticed 
any desire to shirk this responsibility on behalf of 
specialists. But Mr. Theobald has given an insight 
into the experience and skill necessary for a quantity 
surveyor. Now, the specialist's quantities consist of 
only three items — so many yards cube of concrete, so 
many squares or yards of centering, and so many 
tons of steel, and these are freely accepted by con- 
tractors. Why, I could never understand. And then, 
1 am afraid that, say, 99 per cent, of specialists, if 
the quantities turn out all right, take the full credit 
for them ; if they turn out all wrong, they may accept 
the responsibility for the steel, but they are certain to 
say, " We know nothing about concrete and centering ; 
we are not quantity surveyors, we are specialist 
designers." 

KK 



494 THE CONCRETE INSTITUTE 

And he says : — 

" It must surely frequently happen, however, 
that in making the various details it is found 
necessary to alter the drawings from which the 
original quantities were prepared, and the latter 
are, consequently, inaccurate to that extent." 

He further says : — 

" I believe that under the present regime their 
correctness is not guaranteed." 

It is a form of acute inaccuracy to give one item 
of steel as the reinforcement for a building when 
that steel ranges from r 3 ^ in. to ii in. or 2 in. rods. 
That is a form of inaccuracy. It is misleading in the 
highest degree, and I think the specialist should abso- 
lutely refrain from giving quantities unless he is pre- 
pared to give them by employing, as Mr. Vawdrey 
suggests that some of them have on their staffs, quan- 
tity surveyors, trained up in a surveyor's office, or, 
failing that, they ought never to issue quantities. The 
system of employing quantity surveyors as members of 
their staffs is also, of course, very bad. 

Mr. Theobald states that there are four forms of 
contract. I think he might also have included in those 
four the R.I.B.A. form, which is admitted by lawyers 
to be one of the finest forms of contract extant, apply- 
ing to any business or trade ; and he might have 
stated, which is of vital interest, that this R.I.B.A. 
form is issued under two headings — one where quan- 
tities form part of the contract and one where they 
do not form part of the contract, and, as I say, this is 
the finest contract, I suppose, that exists on any busi- 
ness matter, and every member of this Institute would 
do well to get a copy. I am proud to think that this 
contract was drawn up by architects and not by 
engineers. 

There is also another form of contract which he has 
omitted to mention, a very important one, largely 
used for alterations : prime cost plus profit. I am 
not to enter on the ethics of that now, because it is a 
highly complicated form, but in many cases it is ex- 



TWENTY-NINTH MEETING, Dec. 12, 1912 495 

ceedingly valuable, and I think it should have been 
mentioned in an authoritative paper of this sort. 

The whole trend of this paper is, and, I think, quite 
rightly, a plea for the employment of quantity sur- 
veyors, but Mr. Theobald must not be too hopeful. 

Mr. Theobald states that he thinks the engineers, 
and I presume by that he covers specialists, by the very 
reason of their profession are not in a position to 
take off the quantities for their work. Well, of course, 
with that I very heartily agree. 

There is one very extraordinary thing he says with 
regard to the responsibility of quantity surveyors, as 
I think, with his great knowledge and experience of 
quantity surveying, he should be able to give this 
Institute some very interesting facts with regard to 
quantity surveyors' responsibilities ; but he does not 
seem quite sure of his ground. He says : — 

" If I am correct in saying that no responsi- 
bility is taken at the present time, the advantages 
are obvious, both to the building-owner and the 
contractor." 

I am afraid we do not live in a Utopia of this sort. 
We cannot shelve our responsibilities ; we cannot say 
whether we will take responsibility or not. I am 
afraid other people say that for us, and a few words 
from Mr. Theobald with regard to the responsibility 
of quantity surveyors would be very valuable. 

He says, " But until contractors have got used to 
our methods of net measurement. . . . " Contractors, 
not engineers. Surely contractors are used to net 
measurement. In London it is absolutely universal 
to measure net, with the exception of stonework. All 
other materials are measured net, and I do not fathom 
quite what he means when he says, " Until contractors 
have got used to our methods of net measurement." 

THE PRESIDENT :— I will now ask Mr. Theobald 
to reply, but before doing so I wish to say that I have 
a long communication from Mr. A. C. Remnant. It 
will be published in the Proceedings ; it is too long 
to read. If there is anybody here who would like to 
make any written communications, the Secretary will 
be pleased to receive them. Before calling upon 



496 THE CONCRETE INSTITUTE 

Mr . Theobald, I think it is the desire of you all that 
we accord him a most hearty vote of thanks for the 
paper he has read to us on " Bills of Quantities for 
Reinforced Concrete." (Applause.) 

Mr. JOHN M. THEOBALD, F.S.I., M.C.I. :— Mr. 
President and gentlemen, before I attempt to deal in 
detail with the criticism which has been passed on my 
paper, I wish to thank you for the generosity of that 
criticism. I am referring more particularly to those 
gentlemen who are engineers in reinforced concrete, 
as I confess I did not expect the welcome that I have 
received from them. 

I feel that my paper has been read rather under a 
misapprehension. Its chief object was to justify the 
employment of the quantity surveyor, and I only 
touched very lightly upon the question of method of 
measurement. 

The majority of the speakers have confined them- 
selves to criticizing the suggestions in the latter part 
of the paper, and the advisability of the employment 
of a quantity surveyor in connection with reinforced 
concrete work has not been questioned. 

The general consensus of opinion at the last meeting 
seemed to be that the form of contract numbered 4 
in my paper, i.e., the initial schedule and subsequent 
remeasurement, was the most practical solution of the 
problem. 

As the time at my disposal is short I propose only 
to refer to those points which more or less directly 
challenge statements in my paper. 

Dealing with the criticism of Mr. Alban Scott, I 
find I owe him an apology for one sentence which I 
used. I said " the acquaintance of my profession with 
yours is not of long standing." It was obvious that 
I had forgotten for the moment that the membership 
of the Concrete Institute comprised professions other 
than that of engineers in reinforced concrete. As a 
member of an outside profession myself I have no 
excuse for the oversight, and I apologize to him for 
the omission. 

I quite agree with Mr. Bare's remark with refer- 
ence to the question of steelwork in the schedule of 
quantities — assuming that No. 4 is the form of con- 
tract adopted. We must, of course, be furnished with 



TWENTY-NINTH MEETING, Dec. 12, 1912 497 

the weight of the various reinforcements by the 
engineer, as the detail drawings would not be ready, 
and there would be no other means of obtaining it. 

With Mr. Kearn's criticism, and his suggestion of 
including all cuttings in centering, and of measuring 
beams per foot run (the latter suggestion being also 
supported by one gentleman whose name I have lost 
for the moment), I am afraid I cannot agree. The 
cutting and waste on the superficial centering of floors, 
etc., must be measured, and I cannot see any advan- 
tage in measuring beams per foot run, unless the 
depths and soffites are given in each case, i.e., not 
averaged. Mr. Kearns is somewhat inconsistent, 
because he pleads for a shorter bill of quantities, while 
his suggestion of running the beams in various sec- 
tions would tend to unduly lengthen it. 

Mr. Davis's point as to the re-use of centering for 
concrete floors is one with which I am afraid quantity 
surveyors cannot deal. We must measure the entire 
superficial of centering, and leave it to the contractor 
to make such reduction in his price as he thinks 
necessary, after an inspection of the drawings. 

Several speakers have dealt with the measurement 
of items which I have not mentioned. I said in my 
paper that I had only touched on the fringe of this 
question, and had I known the line the discussion was 
going to take, I should have gone much more fully 
into it. 

I quite agree, for example, with Mr. Corderoy's 
contention that the method of measurement of every 
job will differ to a certain extent. In a paper of this 
length it has been impossible to do more than 
generalize, which is all that I have attempted to do. 
If I may presume to advise, I would say, " When in 
doubt, keep the item separate.'* You are then on the 
safe side ! 

I know I am only voicing the wishes of the meeting 
when I offer the President our hearty thanks for his 
lucid exposition of his method of taking out quantities, 
and also for the trouble he has taken to prepare the 
chart which is now on the wall. From a quantity 
surveyor's point of view his short lecture has been 
most interesting, and I feel he is much more compe- 
tent to read a paper on quantities than I. I can only 



498 THE CONCRETE INSTITUTE 

say that, had his methods been adopted by other engi- 
neers in reinforced concrete, I should have had no 
justification whatever for reading my paper. 

Mr. Workman asks me whether quantity surveyors 
would be prepared to take out quantities under the 
conditions he mentioned. I emphatically say, no ! 
We have got to live, too ! As I said in my paper, 
it is the system that is wrong, both from .Mr. 
Workman's point of view and my own. I cordially 
agree with the remarks that have been made by 
several gentlemen with regard to the unfairness of 
architects obtaining tenders on four or five schemes 
simultaneously. By all means select one, have the 
quantities prepared, and a price obtained in com- 
petition. 

Mr. Workman also criticized my allusion to the 
knowledge of our ancestors. I admit that this experi- 
ence is not perhaps of direct assistance in connection 
with reinforced concrete, but it is not absolutely 
useless. They taught us how to measure, and it is com- 
paratively easy to apply their principles to the measure- 
ment of any material that is placed on the market, 
but I have a lot to learn, Mr. Workman, and I admit it. 

Mr. WORKMAN : — I was only pulling your leg. 

MR. THEOBALD :— Well, you did it very success- 
fully. I am sorry, in a way, that your cold prevented 
you from dealing with some of the criticism on 
similar lines ! 

With reference to Mr. Fraser's remarks on the 
question of clients seeing the bills of quantities, if 
he will read my paper again he will see I alluded 
to the " Variations," not the bills. Perhaps my experi- 
ence has been an unfortunate one, but 1 have had a 
great number of clients who have gone very fully 
into the variations. I only hope it is an unusual 
one, and I congratulate Mr. Fraser as much as I 
commiserate myself. Mr. Fraser also accuses me of 
asking a lot of conundrums in the desire to get 
answers ! If he will inform me how I can obtain 
information without asking for it, I shall be glad to 
take advantage of his advice on a future occasion. 

I wrote the paper with the intention of provoking a 
discussion on the question, and, incidentally, learning 



TWENTY-NINTH MEETING, Dec. 12, 1912 499 

a lot. I have provoked the discussion, and I have 
learned a lot. 1 apologize to Mr. Fraser for having 
omitted the two forms of contract to which he refers. 
My sins of omission, I fear, are many, and I can only 
plead, as I carefully mentioned in my paper, that I 
spoke from my own experience. 

Then dealing with the question of " nett " measure- 
ment, to which he, and I think it was Mr. Alban Scott, 
referred. The term " nett " as used by quantity sur- 
veyors is not legally correct, and must be very loosely 
interpreted. Their use of the term, however, is well 
understood by contractors, and can be taken to mean, 
for example, that the floor centering has been deducted 
for the beams, that the stanchions, if measured through 
to floor level, would be deducted from the concrete of 
the floor, and so on. 

There is one more point which has been brought 
to my notice since writing this paper, and it is one 
with which I should have liked to deal at the time. 
I refer to the question of alterations in reinforced con- 
crete from a quantity surveyor's point of view. 

I was shown a bill of quantities a few days ago by 
a contractor in which there was an item for cutting 
away in a reinforced concrete floor to form a well 
hole for stairs (the size was given), including making 
good concrete and reinforcement, and taking all 
responsibility. 

To my mind this method of dealing with an altera- 
tion is absolutely wrong, and I cannot too strongly 
condemn the practice of allowing an inexperienced 
contractor (I use the term " inexperienced " solely in 
this connection) to interfere with reinforced concrete. 
Include the cutting of the hole in your bill of quanti- 
ties by all means, but you should also include a 
provisional amount to allow of the firm of specialists 
under whom the work was originally carried out 
making such alterations in the reinforcement as may 
be necessary. To place the responsibility on the 
builder is unfair both to the client and him. It should 
be placed upon the firm who could in all fairness 
be asked to accept it. 

Before I sit down I wish to thank you. Sir, and, 
through you, the Council of the Concrete Institute, 
for allowing me to read this paper, for the generous 



5 oo THE CONCRETE INSTITUTE 

allowance of time you have given to the discussion, 
and also for the invitation you have extended to the 
members of my profession, which I can assure you. 
Sir, is a compliment very highly appreciated by them. 
Gentlemen, I thank you very much. 

The following communication has been made in 
writing by Mr. A. C. REMNANT, F.S.I.:— 

Whatever methods are adopted for quantities of 
reinforced concrete consistency should hold a 
premier position. Reinforced concrete, as the lecturer 
remarks, has emerged from a healthy infancy and is 
now approaching the adolescent stage ; it remains, 
therefore, for the professions most concerned — viz., the 
engineer and quantity surveyor — to see that any 
methods of measurement adopted are uniformly agreed 
to and standardized, so that the steps of the erstwhile 
infant may terminate at an honourable point instead 
of tottering, in diverse paths at the whim or fancy of 
individual practitioners ; therefore consistency is a 
most essential factor. I may allude to a large work 
I have in hand, where the original quantity surveyor 
in measuring concrete lintels makes no deduction what- 
ever from brickwork where the lintels are 12 in. in 
height and under, but above that height brickwork is 
deducted for the void filled by the concrete lintel. In 
the building I have in mind are fairly thick walls, 
some ranging between 4 ft. and 5 ft. thick ; now, a 
9-in. or 1 2. -in. lintel over an opening in such walla 
is not deducted, whereas a lintel 15 in. high in a 
4^-in. or 9-in. wall is deducted. In the bill of quan- 
tities the item appears as so many thousand feet cube 
of " breeze concrete in lintels and hoisting and fixing 
at various levels, including all requisite moulds." It 
will be seen from the description quoted that no infor- 
mation is given to tenderers as to whether the brick- 
work has been measured net — i.e., voids filled by lintel 
deducted — or that no deductions have been taken. Such 
a course throws a great risk on the estimator, which 
would have been removed had the description of the 
lintels been supplemented by an explanatory note that 
for all lintels above 12 in. high brickwork was de- 
ducted. The lintels in question have been priced at 
the usual rates current where brickwork has been 



TWENTY-NINTH MEETING, Dec. 12, 1912 501 

deducted ; therefore the contractor enjoys the fortunate 
position where 9-in. or 12-in. lintels are in very thick 
wails of being paid for brickwork as well as concrete. 

Well, coming to the latter pages of this paper, on 
page 443, I think any quantity surveyor at any time 
should be prepared to take the responsibility of his 
quantities without the slightly increased fee to com- 
pensate him for the risk. Why reward one for 
sobriety or for the elimination of risks which may 
take place in the hustling between the hours of 8 
and 11 p.m., as outlined on page 438? 

On page 444, as regards pricing, contractors with 
that unfathomable accuracy or speculation gained by 
experience are able to price anything, and the valuation 
of concrete, centering, and reinforcement is therefore 
comparatively simple and easy. I, however, side with 
Mr. Theobald in the desire for separation of the units 
comprising concrete construction. It is quite feasible 
to keep the concrete, centering, and metal separate for 
each floor ; it gives a tenderer the opportunity to 
place slightly higher rates for the higher levels if he 
desires, or he can lump his figures at one uniform 
rate throughout, as improved methods of hoisting 
have reduced the extra costs which used to be incurred 
in the olden days. 

The crux of reinforced concrete is the centering — 
one might almost say its mainstay, even if of only a 
temporary nature — and I consider more detail should 
be given to the measurement of this. I agree with 
Mr. Theobald that openings should be deducted in 
every case, that centering should be described " as 
measured net, all openings deducted " ; we then know 
where we are. The centering to openings could be 
taken as numbered items or as feet run of " casing to 
sides of concrete so many inches thick in openings 
and to include for necessary struts and supports." 

Mr. Theobald dismisses floor centering without dis- 
cussion. Considerations should, however, be given 
to floor centering in small bays or panels where large 
numbers of beams are involved. The finesse of a 
concrete specialist who on a floor of perhaps 40 ft. 
by 60 ft. may have three or four varying thicknesses 
of floor concrete, due to the size of the bays, demands 
attention at the hands of the measurer as involving 



502 THE CONCRETE INSTITUTE 

a certain amount of additional labour and waste,, 
although this is a matter more perhaps for adjustment 
in beam measurements. 

Coming to these, Mr. Theobald suggests these should 
be measured by the foot super, and where 18-in. girt 
and under, at per foot runs. As surveyors we are 
used to descriptions of " casing to sides and soffits 
of beams," but I suggest that every estimator seeing 
such a description imagines that the sides of beams 
are, at any rate, equal, but when confronted by varying 
thicknesses of floor, such as I have just outlined, may 
when called on to do the work find a difference of 
77 in. between the sides, a difference which entails 
waste and labour out of proportion to the financial 
benefit derived in reducing the width to suit these 
varying conditions. Personally, I think, even if 
involving more items, it would be better to measure 
all beams by the foot-run, giving a sketch showing 
the width of soffit and actual heights of the sides. 
Estimators have then something definite to work on, 
and we as surveyors would not be confronted when 
adjusting variations with vexatious claims due to 
insufficient description. 

As regards concrete, this might be separated as 
stated, but as regards beams only that portion below 
the decking should be so measured. I mention this 
as in my experience I have come across reinforced 
concrete measurements where beams are taken to top 
of decking, then the decking measured right over 
without deduction for the beams and to supplement all 
stanchions and columns measured from floor to floor, 
so that at the intersection of the head of a stanchion 
crossing of beams and decking one gets a glorious 
overlapping of material and consequent values. There- 
fore net measurements are strongly advocated, and 
let the work be valued on its own merits and not on 
its excesses. 

As regards steel reinforcements, these being of small 
scantling are usually quite capable of being bent cold, 
and the weight descriptions should include a note to 
the effect that all bends and hooked ends are to be in- 
cluded. I think the whole question of reinforcement 
should be governed by weight measurements rather 
than numbered items for stirrups. Estimators know 



TWENTY-NINTH MEETING, Dec. 12, 1912 503 

by experience what this metal with its labour costs 
per cwt., but when broken into small items up 
goes the price and the estimator loses the job. The 
wiring of reinforcement members, being a compara- 
tively small factor, might be included in the descrip- 
tion. I think reinforcement might reasonably be 
divided and described as in floors, beams, and 
stanchions. 

THE PRESIDENT :— I will now call upon Mr. 
Laurence Gadd to read his paper entitled " Action of 
Acids, Oils and Fats upon Concrete." 

Mr. W. LAURENCE GADD, F.I.C., M.C.I. :— 
Mr. President and gentlemen, in addressing this short 
paper to the Concrete Institute, I am conscious that 
it is a very scrappy contribution, but the choice of the 
=aibject was not mine. It was suggested to me by 
the Secretary some little time ago — at any rate, I did 
not question his authority, and, unfortunately, I have 
not had the time to go into a subject like this as 
thoroughly as it ought to be gone into. I had there- 
fore to fall back very largely upon work which I had 
done at various times previously for my own informa- 
tion. I therefore want to say I do not present mis 
paper as in any way a comprehensive treatment of the 
subject, but as offering a small, a very small, contribu- 
tion to the study of the material which this Institute 
is so greatly interested in. 

Mr. GADD then read his paper — 



ACTION OF ACIDS, OILS AND FATS 
UPON CONCRETE 

With regard to the mineral acids— e.g., hydro- 
chloric, nitric, and sulphuric acids — there is little to be 
said. Neither cement nor concrete will withstand the 
action of these acids, which decompose and dissolve 
the constituents of cement, even in dilute solution. 
Even a weak acid, like carbonic acid, has a distinct 
action upon cement, which, suspended in water, can 
be practically entirely carbonated by passing a current 
of carbon dioxide into it. 



504 THE CONCRETE INSTITUTE 

The action of organic acids, such as lactic and 
butyric acids, formed by the fermentation of milk or 
butter ; tannic acid, occurring in tanning liquors ; 
tartaric and citric acids, and acetic acid in vinegar 
or stale beer, is not so marked ; but it is very prob- 
able that the whole of the series of higher fatty acids 
will be detrimental to concrete. 

In most cases the action of the organic acids is 
confined to a combination with the calcium hydrate 
liberated when cement or concrete is gauged with 
water ; but, as the organic lime-salt formed has no 
cohesive strength, the concrete must be deteriorated 
to a greater or less extent, depending upon the quantity 
of the acid and on its combining weight. 

The tendency of organic acids to combine with 
carbonate of lime is much less than with hydrate of 
lime, and it follows that an acid which would be 
dangerous in contact with green concrete might be 
perfectly harmless in contact with old or indurated 
concrete. Thus, stale beer has a distinctly detrimental 
action upon new work, but once the concrete has 
indurated by exposure to air for some time, the acid 
of sour beer has little action upon it. . 

Fresh beer has, itself, a weakening action on green 
concrete, as the following experimental results show ; 
but the deterioration in this case is due to the sugar 
and other organic constituents of the beer, and not 
to the action of beer acids. 









TABLE A. 








Tt 


wsile 


Strength 


(lbs. per 

Neat. 


square 


inch). 

Sand (3 : 1). 


\ept in water 






3 Days. 
630 
620 

625 


7 Days. 

765 
730 

747 


28 Days. 
1,020 

g6o 
99o 


7 Days. 2R Day 
340 425 








Plunge 


pat — Sound. 




vept in beer 






620 
560 

590 


710 
675 

6Q2 


810 
75o 

780 


300 360 








Plunge 


pat — Failed. 





TWENTY-NINTH MEETING, Dfx. 12, 1912 505 

The test pieces were gauged with water in the usual 
way, and after twenty -four hours in moist air were 
immersed in water and beer respectively until due 
for breaking. 

One of the commonest forms of acid action to 
which building material is subjected is that of 
sulphuric acid, derived by oxidation from the 
sulphurous gases present in the atmosphere of large 
towns. This is noticeable on Portland stone, of which 
many buildings in London are constructed. It appears 
to be less marked on concrete buildings, possibly 
for the reason that the surface pores of concrete 
become closed with a deposit of calcium sulphate, 
which affords protection from further action of the 
acid. 

Lactic acid is produced by the fermentation of 
milk, brought about by the micro-organism Bacterium 
lactis, and is a possible acid to come in contact 
with concrete structures in farm buildings. The 
action of this acid is confined to combination 
with calcium hydrate, forming calcium lactate 
(Ca (C 3 H 5 3 ) 2 -J- 5H 2 0). This salt is soluble in 
water, and in wet situations would be readily leached 
out of concrete in which it were formed, so that the 
deleterious effect of lactic acid would consist in the 
gradual removal of the lime hydrate, which plays 
an important part in the induration of concrete. For 
practical purposes, it is probable that this action would 
be very small. 

The following tests show the effect of prolonged 
immersion in a solution of lactic acid, prepared by 
fermenting milk, and removing the curd : — 

TABLE B. 

Mortar 4 : 1 (ordinary building sand). 

Test pieces 1 day in air, 27 days and 3 months in the whey and in 
water respectively. 





Tensile 


Strength. 


Crushing 


Strength. 




28 Days. 


3 Months. 


28 Days. 


3 Months 


In whey 


• •• 430 
440 


470 
470 


4,700 
4.900 


6,700 

6,000 




435 


470 


4,800 


6,350 


In water 


400 
410 


495 
480 


4,600 
4.750 


6,800 
7,000 




405 


487 


4,675 


6,900 



506 THE CONCRETE INSTITUTE 

This is, of course, a much more drastic test thaei 
would be at all likely to occur in practice, but the 
results do not disclose any marked deterioration caused 
by the lactic acid. 

Concrete vats would appear to be suitable for 
tanning operations, and the possible action of tannic 
acid becomes of importance. This acid, of which 
gallotannic acid (C u H 10 O 9 ) may be taken as a type, 
is again an organic acid which combines with calcium 
hydrate to form calcium tannate, but as the combining 
weight of tannic acid is high — sixteen parts by weight 
combining with only one part of calcium — the probable 
action is not very serious . 

The following tests were carried out in order to 
ascertain the effect of gauging with a solution of 
tannic acid (two grams per litre ) and, for comparison, 
test pieces of the same cement were made in the 
usual way, gauging with water only : — 











TABLE C. 
















T 


ensile Strength. 














Neat. 






Sand (4:1) 


. 




7 Days. 


1 Mon. 


2 Mons. 


3 Mons. 
Gaug 


6 Mons. 7 D.iys. 
cd with Tannic Ac 


1 Mon. 

id. 


2 Mons. 


3 Mons. 


6 Mi ms. 


820 


865 


060 


880 


870 300 


345 


375 


375 


400 


795 


820 


920 


875 


860 290 


325 


355 


3(10 


360 


790 


845 


— 


— 


— 290 


V5 


— 


— 


— 


80 1 


845 


940 


877 


865 203 


331 


365 


367 


380 








Gauged with Water. 










845 


940 


1)30 


940 


965 335 


345 


390 


415 


430 


800 


920 


920 


920 


950 315 


340 


385 


390 


435 


830 


905 


— 


— 


— 310 


340 


— 


— 


— 



825 921 925 930 957 320 341 387 402 432 

Crushing Strength. 

Ganged with Tannic Acid. 

7,000 9,000 11,600 11,300 12.700 3,000 4,600 5,700 5,800 6,900 

7,100 9,300 „ 10,950 11,200 12.650 3,200 4,450 5500 6,050 6,650 

7,000 9,550 — — 3,000 4,550 — — 

7.033 ^266 11,275 11-250 12,675 3.o66 4,533 5.6oo 5,925 6,775 

Ganged with Water. 

7,600 9.75° 11,000 12,300 14,600 3,400 4,900 5,250 6,800 7,150 

7,750 10,000 11,700 11,850 13,900 $,350 5,150 5,000 6,500 7,500 

8,150 9.900 — — 3,350 4,800 — — — 

7.833 0..SS3 11,350 12,075 14,250 3.366 4,950 5,175 6,650 7,325 



TWENTY-NINTH MEETING, Dec. 12, 1913 507 

One specimen for each period was removed from 
the water after twenty -six days, and kept for the 
remainder of the time in air. 

These gave the following results : — 

TABLE D. 

Tensile Strength. 

Neat. Sam.. 

2 Months. 3 Months. 6 Months. 2 Months. 3 Months. 6 Months. 

Gauged with Tannic Acid. 

880 815 815 380 450 460 

Hanged with Water. 
910 885 890 420 515 510 

Crushing Strength. 

Gauged with Tannic Acid. 

10,600 11,050 12,150 5.°°° 6,35° 6,700 

Gauged with Water. 
10,750 11,300 12,850 5.35° 6,700 6,850 

It will be seen from the above that the test pieces 
gauged with tannic acid solution gave lower tensile 
and crushing strains, but the difference is not sufficient 
to mark any great deterioration. 

Oils and Fats. 

Proposals have of late been made, particularly on 
the other side of the Atlantic, to incorporate a certain 
small amount of oil or fat with concrete, with the 
object of giving the same dustless, waterproof, and 
other qualities. What we might almost call the 
natural instinct of the concrete worker has, however, 
always led him to avoid oil or grease as far as 
possible, and he has been right. Whether we accept 
the crystallisation theory, or the colloidal theory of 
the setting of cement, the presence of oily matters 
must interfere with the process of setting, even 
assuming that the oil has no chemical action with 
the constituents of the cement. Furthermore, oil does 
not readily mix with water and has a tendency to 
collect in globules, which, however small, are a source 
of weakness to the concrete. 

Many oils and fats react chemically with the cement 



508 THE CONCRETE INSTITUTE 

constituents, and in this class must be placed the whole 
of the oils and fats of animal or vegetable origin. 

These substances consist of the glycerides of various 
fatty acids, such as stearic, palmitic, and oleic acids, 
although the acids may be present in the free state, 
as, for instance, in palm oil, which may contain from 
50 per cent, to 80 per cent, of free acids calculated 
as palmitic acid. 

The glycerides of the fatty acids, which constitute 
the neutral oils and fats of animal or vegetable origin, 
are readily decomposed, or saponified, by certain metals 
and metallic salts, and by all alkalies, including calcium 
hydrate, which we know is a constant product in 
cement or concrete which has been gauged with water. 
The result of this saponification is the decomposition 
of the oil with the formation of a metallic or alkaline 
salt or soap, and the liberation of glycerin. 

Thus, tallow is saponified by calcium hydrate, 
according to the following equation : — 

2 C 3 H 5 (C l8 H 35 2 ) 3 + 3 Ca(OH) 2 = 2 C 3 H s (OH) 3 + 3 Ca(C l8 H 35 2 ) 2 

Tristearin (tallow) + calcium hydrate = glycerin + calcium 
stearate (lime soap). 

Calcium stearate is a whitish, friable material, in- 
soluble in, and immiscible with water ; whilst the 
lime soaps of other fatty acids commonly occurring 
in oils and fats, are slimy and sticky substances which, 
although water repellents, do not, so far as my experi- 
ments show, render concrete less permeable to water, 
and decidedly reduce the tensile and crushing strength. 

By this process of saponification, which takes place 
rapidly under the influence of heat and more slowly 
in the cold, cement or concrete will certainly be 
injured by the admixture of any animal or vegetable oil 
or fat ; and if the concrete be green or new, there is 
some liability of damage being done to it by mere 
contact, such as might occur from constant drippings 
of oil upon it. 

Calcium carbonate has not the power to saponify 
neutral oils or fats,, so that oil in contact with indurated 
concrete, in which the calcium hydrate has been largely 
converted into carbonate, would have little deleterious 
action. 



TWENTY-NINTH MEETING. Dec. 12, 1912 509 

Mineral oils and greases, which are hydrocarbons, 
are of a different constitution from that of the animal 
and vegetable oils, and are incapable of saponification. 
They have, therefore, no injurious action from this 
particular cause, although they weaken the strength 
of concrete for physical or mechanical reasons. 

This is experimentally confirmed by the following 
series of tests on sand mortar 3:1, in which various 
oils and fats were incorporated to the extent of T \ of 
the weight of cement used. 

TABLE E. 
Crushing Strength. 

Oil added— 7 Days. 1 Month. 3 Months. 6 Months. 12 Months. 

None ... 4,000 6,200 7,000 8,300 8,750 

(kept in water) 4,200 5,700 7,350 8,850 8,800 

4,050 5,450 7,200 8,600 8,900 

4,o83 5,783 7T183 8,583 8,816 

(kept in air) 4.200 5,5oo 6.550 6,850 7,100 

4,400 4.700 6,200 6,700 7,150 

3,900 4.900 6,900 7,000 7,600 





4,166 


5.033 


6.550 


6,850 


7,283 


Vaseline 

Ikept in water) 


2,700 
2,900 

2,750 


4,250 
3,850 
3oOo 


3i55° 

3,95o 
4,100 


4,800 
4,550 
4,400 


5,250 
4,800 
5,100 




2,783 


3,866 


3.866 


4,583 


5,050 


kept in air) 


• 3J50 
3.300 
3,300 


2,150 
2,200 
1,900 


4.400 
4,400 
4.400 


4,600 
4-550 
4.450 


4,600 
4.550 
4,750 




3.250 


2,083 


4.400 


4.533 


4,650 



Cylinder oil 3,600 4,800 5,000 6,200 5,400 

(kept in water) 3,550 4,35© 4,600 5,900 5,000 

3,200 4,200 4,500 5,600 5,250 

3,45° 4450 4,700 5,900 5,216 

(kept in air| 2,100 2,900 4,600 4,600 4,300 

2,600 2,600 4,300 4,200 4,700 

2,650 2,650 4,150 4,400 4,500 

2,450 2,716 4,350 4,400 4,500 

LL 



5io 



THE CONCRETE INSTITUTE 





TABLE 


E — con 


tillUCd. 








Crushing Strength. 






Oil added— 


7 Days. i 


Month. 


3 Months. 


6 Months. 


12 Months. 


Lard 

(kept in water) 


1,150 
1 ,300 
1,300 


1-950 
I.4OO 
I,700 


2,900 
2,900 
2,500 


3,500 
3,000 

3,200 


3,400 
3,600 
3,200 




1,250 


1,683 


2,766 


3,233 


3,400 


(kept in air) 


1,000 


IJOO 


2,000 


2.700 


2,200 



Cotton-seed oil 
(kept in water) 



i.ooo 
1,250 



1.083 



950 
900 
95o 



i,55o 
1,700 



1,650 

1,700 
1,900 
i,75o 



933 



1.783 



2,100 
1,900 



2,000 

2,300 
2.400 
2.700 



2,466 



2,700 
2,500 



2,633 



3,500 
3,800 
3,500 



2,350 
2,600 



2,383 



3,900 
3,800 
3,450 



3,600 3.716 



(kept in air) 



Colza oil 

(kept in water) 



(kept in air) 



1,000 
900 
750 

833 



1,150 
1,050 
1,100 

1,100 



1,000 
1,200 
1,200 

1,133 



1,900 
1,700 
1,500 

1.700 



1,600 
2,000 
1,850 

1,816 


















100 


O 





500 


700 


100 


O 





500 


800 


100 








550 


700 


100 








516 


733 


200 








500 


600 


200 








400 





200 








400 





200 








433 


200 



In the above table the first two oils are mineral, the 
third is animal, and the last two are vegetable oils. 

The results show that the vegetable and saponifiable 
oils cotton -seed and colza are absolutely destructive 
to concrete, and that the mineral oils, which are not 
saponifiable, reduce the strength very materially when 
mixed in small proportion with the mortar. It will be 
noticed that the strength at twelve months is less than 
at six months in the cases of cylinder oil (mineral), 
lard (animal), and colza oil (vegetable 1. 

When testing samples of cement for tensile strength,. 



TWENTY-NINTH MEETING, Dec. 12, 19 12 511 

which is commonly done now by users, I have observed 
that many operators use colza oil for the purpose of 
greasing the briquette moulds. The film of oil which 
remains, or should remain, on the moulds is, of course, 
very thin, but colza oil cannot be considered a suitable 
oil for the purpose, seeing that it has so great an action 
upon cement. Briquette moulds should be oiled with 
mineral oil, or a mixture of heavy mineral oil and 
paraffin . 

In order to test the waterproofing qualities of oil- 
mixed concrete, flat slabs of similar mixtures to the 
above were made in a standard manner, and, after 
twenty-eight days, were submitted to percolation tests 
by subjecting them to a water pressure of 50 lbs. 
per sq. in., in such manner that the water forced 
through the slabs could be collected and measured. 
The following table sets forth the results obtained : — 

table F. 

Slabs kept 28 days in water before testing. 

Size of slabs — 10 x 10 x 3 in. 

Area subjected to water pressure — 16 sq. in. 

Water Percolated through the Slabs. 

Oil added. 
None (cement only) 

Vaseline 

Cylinder oil ... 

Lard 

Cotton-seed oil 

Col/a oil ... ... 

(2) 

It is to be noted that these slabs were not intended 
to be made absolutely watertight, the object being to 
obtain a comparison. Leighton Buzzard sand was 
therefore used, and the results show that under identical 
conditions sand mortar without any addition of oil was 
more watertight than with any of the oils or fats tried. 
The addition of lard, colza, and cotton-seed oils to 
the extent of less than 2 - 5 per cent, on the weight of 
the concrete prevented the slabs from setting properly 



Lil 


:res per Hour. 


(1) 


47 


(2) 


177 


(I) 


13400 


(2) 


340-0 


(I) 


695-0 


(2) 


26o - o 


(I) 


Slab broke 


( 2 ) 
(I) 


" 


(2) 


41-2 


(I) 


Slab broke 



5i2 



THE CONCRETE INSTITUTE 



even after twenty -eight days, and they were unable to 
withstand the water pressure placed upon them. 

Mr. R. \V. VAWDREY, B.A., Assoc. M. Inst. C.E. 
(Member of Council) : — Was that 7.\ per cent, of the 
water ? 

Mr. GADD : — No ; it was 2\ per cent, of the 
cement used ; one -tenth of the dry cement. 

In order to test the effect of oils upon concrete 
gauged with water in the usual way a number of 
briquettes was prepared, consisting of four parts of 



Immersed in — 

Water 



TABLE G. 
Tensile Strength. 

i Mon. 3 Mons. 6 Mons. 12 Mons. 
• 445 540 5°o 605 
445 5io 530 505 

445 5^5 545 6 °o 



Crushing Strength. 

1 Mon. 3 Mons. 6 Mons. 12 Mons. 



4.600 

4750 



4.QOO 
5,800 



6.650 
6,250 



7.4OO 

7,850 



4.675 5.350 6,450 7.025 



Paraffin 



480 

420 



5i6 
565 



550 620 
5.10 585 



4,500 
4.500 



4.650 
5.200 



6.500 
6.200 



1,775 1.250 



7.150 
7400 





450, 


540 


530 


602 


4,500 


4,925 


6.350 




Turpentine 


435 
410 


500 
450 


520 

4*5 


610 
575 


4-35° 
4,500 


5.200 
5.400 


5.250 
5oOO 


5,900 

5.800 




422 


475 


502 


592 


4425 


5.300 


5,375 


5.850 


Heavy mineral oil 


450 
405 


530 
550 


570 
565 


545 
510 


4.400 
4,800 


6,300 
6,700 


6,500 
6.500 


5,850 

5,700 




457 


540 


567 


527 


4,600 


6,500 


6,500 


5-775 


Cotton-seed oil 


















2.350 
1.200 


800 
1.700 


800 
1,000 


1,900 
1,650 



900 1,775 



ordinary building sand to one part of cement ; and 
after twenty-four hours in moist air these were 
immersed in various oils for periods of one, three, six. 
and twelve months, at which dates the tensile and 
crushing strengths were ascertained. 

A further series of similar test pieces was prepared, 
but in this case the briquettes and cubes were allowed 
to mature in air for twenty -eight days before they were 
immersed in the oils. 



TWEXTY-XIXTH MEETING, Dec. 12, 1912 513 









TABLE H. 












Ten 


SILE 


STRENGTH. 


Crl 


shing Strength. 


Immersed in — 


1 Mon. 3 


Mons. 


6 Mons. 


12 Mons. 


1 Mon. 


3 Mons. 


6 Mons. 12 Mons. 


Water 


485 

450 


515 
500 


565 
530 


570 
560 


5,400 
3,650 


6. 1 50 
(1,700 


6,900 
6,600 


7,000 

7.300 




46/ 


507 


547 


565 


5.525 


6.425 


6J50 


7,150 


Paraffin 


400 
400 


425 
38o 


465 
460 


470 
425 


4,200 
4i°5° 


4.850 
4.350 


4,850 
5.150 


5,400 
5,900 




400 

400 
400 

400 


402 

345 
340 

342 


462 

320 
315 

317 


447 

430 
425 

427 


4-425 


4,600 

3.900 
3.550 

3725 


5,000 


5,650 


Turpentine 


4,000 
4.250 

4.125 


4.500 
4,550 

4.525 


4,500 

4,700 

4,600 


Heavy mineral oil 


460 

440 


410 
390 


430 
425 


45o 
45o 


4,150 
4,500 


5.500 
5.400 


4,500 

4,200 


4,800 

5,250 




45° 


400 


427 


450 


4-325 


5.450 


4.350 


5,025 


Cotton-seed oil 


• 75 
50 














2,700 
2,650 


O 














62 











2.675 












These tests again bring out the destructive action of 
saponifiable vegetable oil, the test pieces immersed 
in cotton-seed oil being reduced to mud in less than 
three months ; and although the mineral oils and 
turpentine had much less marked effects, they never- 
theless materially reduced the strength of the concrete 
immersed in them. 

The broken briquettes, which had been immersed 
in oils for twelve months, were freed from the sand,. 







TABLE 


I. 








A. 


B. 


c. 


D. 


E. 


Briquettes immersed in : 


Paraffin. 


Turpentine. C 


blinder Oil. 


Cotton-seed Oil. 


Cotton-seed Oil 




Per Cent. 


Per Cent. 


Per Cent. 


Per Cent. 


Per Cent. 


Silica 


2074 


1879 


20-12 


16-08 


13*59 


Alumina and iron 












<>.\ide ... 


C/46 


8-24 


9 -oo 


OUO 


4-91 


Lime 


54'29 


4978 


53 "3 1 


4048 


32-3I 


Magnesia ... 


1-28 


1-27 


1-48 


•00 


•82 


Sulphuric anhvd 


1-32 


1-32 


1-30 


107 


•97 


Combined oil | 
Combined water i 


12-lS 


6-50) 
12-50; 


12-62 


i>S'3o 
'5 75 


31-76 
14-19 


P"ta»h and soda ... 


73 


i-6o 

10000 


2-17 


•96 

ioo-oo 


i-45 




1 0000 


1 0000 


ioo-oo 



514 THE COXCRETE INSTITUTE 

as far as possible, by sifting, and from adhering oil 
by repeated extractions with ether, and then submitted 
to chemical analysis. Eliminating the traces of sand 
still remaining in the samples, the results were as 
given in Table I on preceding page. 

Samples A, B, C, D had been one month in air 
and twelve months in oil. Sample E was kept only 
one day in air before immersion for twelve months in 
oil. 

The results show that concrete in contact with certain 
oils suffers chemical change by the combination of the 
liberated calcium hydrate with the fatty acids of the 
oil, as much as 32 per cent, of oil being combined in 
a. period of twelve months, when green concrete is 
immersed in cotton -seed oil. 

This amount of oil in combination as calcium oleate 
and stearate is quite sufficient to account for the dis- 
integration of the concrete. 

It will be observed that in the parallel cases of 
briquettes immersed in cotton-seed oil after one 
month's induration, and after one day only in air 
respectively, the action of the oil is much less marked 
in the former than in the latter, due to the fact, as 
mentioned earlier in this paper, that fatty acids do 
not react with calcium carbonate. 

The conclusions I draw from theoretical and experi- 
mental data are : — 

1 . That the addition of oil or fat, of any kind, to 
concrete results in a weakening of the strength. 

2. That animal and vegetable oils have a direct 
action on green concrete, and in time will bring about 
its destruction. 

3. That indurated concrete is less liable to be 
attacked by oils and fats. 

4. That oil -mixed concrete is not rendered more 
waterproof. The least permeable concrete is, in my 
opinion, a dense mortar in which the aggregate is 
properly graded to fill the voids. 

DISCUSSION. 

^ THE PRESIDENT :— I think we must thank .Air. 
Gadd for his interesting paper. One thing he had 
proved is this : that the addition of any extraneous 



TWENTY-NINTH MEETING, Dec. 12, 1912 515 

matter to Portland cement does not improve its 
strength. It is well known, and I am glad that he 
has proved it by experiment, that where acids and 
oils generating acid come into contact with concrete, 
then destruction is bound to take place sooner or 
later. In amplification of his paper, I wish to give 
some experiments I had made for me some six or 
seven years ago as to the action of creosote upon con- 
crete. I was designing a tank to contain creosote, 
and I wanted to find out what the action of creosote 
would be upon concrete which had been kept in water 
for six months and then immersed in creosote. The 
concrete was composed of 5 to 1, 3 to 1 sand, and 
neat cement, and in every instance where it had been 
kept in creosote for eighteen months the strength was 
higher than when it was kept in air. In the case of 
the neat-cement cubes, after eighteen months' immer- 
sion the crushing amounted to 1,363 tons a square 
foot, or 9/46 tons a square inch. It had been kept 
under normal conditions — that is to say, in tempera- 
tures ranging from 35° to 6o° Fahr., and during 
the whole eighteen months for the neat -cement tests 
the creosote had not permeated it at all ; and for the 
concrete cubes it had only indurated to about one- 
eighth of an inch, except where one sample was made 
with a very soft and porous stone ; then it went right 
through. But when the same neat cubes were placed 
in a chamber where the creosote was heated to 1 20 . 
in less than fourteen days it went clean through the 
specimens. 

I will now call upon Mr. Butler to open the dis- 
cussion. 

Mr. D. B. BUTLER, Assoc. M. Inst. C.E., F.C.S. 
(Member of Council) : — I wish to thank Mr. Gadd 
for his very able contribution to our proceedings. 
Only those who have had occasion to undertake 
research of this kind can realize the immense amount 
of work involved. Mr. Gadd was modest enough to 
say at the commencement of the paper that he had 
only touched the outside of the question, but I can 
quite sympathize with him for the amount of work he 
must have undertaken to get all these data together. 

It is a little peculiar that the very first substance or 
liquid which Mr. Gadd mentions is beer. Well, gentle- 



516 THE CONCRETE INSTITUTE 

men, I think as a rule the effect of beer on concrete 
is indirect, very indirect, and it has been known to 
have very bad effects. But I would like to ask Mr. 
Gadd, referring to his beer tests, as to what effect the 
beer had on the setting of the cement. I see he men- 
tions that the plunge pat in water was sound, whereas 
the plunge pat in beer failed. Mr. Gadd, in most of 
his experiments, only gives the average of two cubes 
or briquettes at each date. I quite appreciate the 
immense amount of work it would have involved to 
give the usual average of five or six, but, referring to 
Table B and the result of the three months' crushing 
tests, if he had happened to have taken only one cube 
instead of two he might conceivably have got 6,700 
in the whey and 6,800 in the water, or practically the 
same. This shows the necessity in all such experiments 
of taking a fair average ; two is not enough. 

With regard to Table C, where comparative tests 
are given with tannic acid and water, in this experi- 
ment the test-pieces in each case were mixed with 
a solution of tannic acid. That seems to me to be 
scarcely so practical as it would have been if the test- 
pieces had been made with water in the ordinary 
way and immersed in a solution of tannic acid. We 
do not as a rule, I believe, gauge our briquettes or 
concrete with tannic acid, although, as Mr. Gadd 
suggests, the concrete is sometimes subjected to the 
liquids resulting from tanning. 

On page 507,, I quite agree with Mr. Gadd's remark 
where he refers to what he calls the natural instinct 
of concrete-workers in avoiding oil or grease of any 
kind. We know that before moulding briquettes or 
other test -pieces we always oil our moulds slightly. 
But do we oil them to make the cement stick to them 
or otherwise ? This seems to me a very fair answer 
to those who advocate mixing oil of any kind with 
cement. 

In Table E, on page 509, he gives the results of 
various vaselines and oils mixed with cement. I should 
just like to ask Mr. Gadd how, seeing that water will 
not mix with oil properly, he managed to incor- 
porate those small proportions of vaseline and oil with 
the concrete. It would be of interest to know his 
modus operandi. 



TWENTY-NINTH MEETING, Dec. 12, 1912 517 

Referring to the same Table E and the last series 
relating to colza-oil, it is a little curious that the 
seven days' tests show a small but distinct crushing 
strength, while at one month and three months they 
show no strength at all ; then they harden again, and 
at six months and twelve months they have gained still 
further strength. It is very curious, and I should 
like to know if Mr. Gadd can explain it. Why a 
material developing strength at seven days should show 
nothing at all at one month and three months, and 
then again develop strength at six and twelve months, 
seems to me a little inexplicable. 

I am still asking for information, Mr. Gadd. It 
would be interesting to have some particulars of the 
method in which you carried out the percolation tests. 
Some twenty-five years ago I helped my old chief, the 
late Henry Faija, in his experiments with regard to 
the forced percolation of sea-water through concrete, 
and in that case we used i^-in. briquettes, composed 
of 3 to 1 sand. We fixed a brass clamp top and 
bottom of the briquette, to which was attached a screw 
nozzle leading to a pipe, which was attached to a 
water tank 1 5 ft . above, so that in that way we got a 
1 5 -ft. head of water forcing through the briquette. 
We found that after a time the percolation ceased 
entirely, both with sea water and fresh water, owing 
to the blocking up of the pores. 

Referring to Table G, where Mr. Gadd immerses 
his test-pieces in various oils compared with water, 
it seems rather drastic treatment to immerse a briquette 
in oil or turpentine. But a rather curious result there 
is that the tensile strength in the cotton-seed oil is 
absolutely nil in each case, whereas the crushing 
strength varies from 900 lb. to 1,700 lb. at various 
dates. The same kind of irregularity occurs in 
Table H, where the cotton-seed oil at one month gives 
only an average of 62 lb. tensile, but an average of 
2,675 crushing. Now, as Mr. Gadd is aware, the 
usual ratio between tensile and crushing stresses is 
somewhere about 1 to 10 — that is, the crushing is 
about ten times the tension. It is a little curious that 
in this case it should be only about 1 to 40, roughly 
speaking. 

Re Table F, I should like to ask Mr. Gadd if, in 



5i8 THE CONCRETE INSTITUTE 

addition to the analyses of the briquettes immersed 
in the various kinds of oil, in which he gives the 
combined oil and combined water, he also analysed 
a briquette immersed in water only, so as to determine 
the amount of combined water in it ; that would be 
useful information, compared with the combined water 
in the other test -pieces. 

Mr. A. ALBAN H. SCOTT, M.S.A. (Member of 
Council ) : — I have very great pleasure in second- 
ing this hearty vote of thanks to Mr. Gadd for his 
most interesting paper. I cannot enter into it from 
the chemist's point of view, but I know from the 
practical point of view it will be extremely useful 
to us. 

There is rather a curious coincidence in Table E. 
The crushing strength of the cement at seven days is 
about 4,000, and at twelve months it is almost all the 
way through just double that strength. It is extremely 
interesting because it is fairly consistent, with the 
exception of about two in the Table. 

With regard to the percolation of water through the 
cement, we were architects for a very large reinforced 
concrete tank about eighteen months ago, and it had 
very slight leakages at first, but all those pores are now 
filled up, and I believe that is the usual experience 
with concrete subjected to a head of water, that it does, 
if properly made, become eventually more watertight. 

Mr. BUTLER : — It depends on the filtering proper- 
ties as to how close the concrete is. If the concrete is 
too porous, of course it will go on. 

Mr. ALBAN SCOTT : — Assuming, of course, it is 
fair average concrete for that class of work. But an 
interesting thing which our client did in that case was 
this : he threw oatmeal into the water, and whether 
it was the oatmeal that gradually flowed to the point 
of leakage that did actually fill them up, or whether 
it was due to the action of the cement is questionable. 
Mr. Butler thinks probably it would be the oatmeal ; it 
is quite a good thing. 

THE PRESIDENT :— When a boiler leaks, people 
put in oatmeal or sawdust. 

Mr. ALBAN SCOTT :— Well, it is quite good in 



TWENTY-NINTH MEETING, Dec. 12, 1912 519 

concrete tanks I think. Mr. Butler mentioned a ques- 
tion of the number of cubes tested. We find that in 
our test-cubes we cannot rely on anything less than 
five to get a good average. Not that I am in any 
way criticizing the small number given here, because 
the data given is most valuable, and must have taken 
up a very considerable amount of time. 

Taking Table F for vaseline, there you get 
No. (1) i340 - o, No. (2) 340-0. With those two 
you cannot get a proper average. We find, in our 
experience that five is a proper number ; we make 
six tubes and keep one for further tests or examina- 
tion if necessary. 

Mr. R. W. VAWDREY, B.A., Assoc. M. Inst. C.E. 
(Member of Council) : — I should just like to ask 
the author a question. To what extent does he think 
that the weakening of the concrete, either in tension 
■or compression, is due to the actual diminution of the 
size of the concrete ? I take it that in some cases at 
any rate, where the action on some of his briquettes 
jvas very marked, as in the case of colza-oil, there 
was an actual diminution in the size of the block. 
Apart from that, however, there must often be a con- 
siderable proportion of the interior of the block or 
briquette that is quite unaffected. It would be rather 
interesting to know, in conjunction with the results 
which he obtained, what area of the cube or briquette 
was actually affected by the oil. In some cases it need 
not be necessarily affected throughout its depth. 

Also, as unfortunately I am not a chemist, I should 
be glad if the author would explain exactly what is 
meant by saponification of the oil. It appears that 
any oil which is subject to that process is very 
deleterious, whereas oil which is not capable of under- 
going that process does not affect concrete. What 
really is the cause of that ? 

I should also like to add my word to the remarks 
of the other speakers in thanking the author for his 
paper. I think it is impossible to conceive a paper 
which is more valuable to the users of concrete than 
that which he has just read. 

Mr. PERCIVAL M. FRASER, A.R.I.B.A., M.C.I. : 
— I would like to ask one question, Mr. President. I 



520 THE CONCRETE INSTITUTE 

am afraid I am not an expert in oils. Are any of the 
oils stated here volatile oils? 

Mr. GADD : — Oh. no. not volatile, except in so 
far as paraffin or turpentine are volatile. 

Mr. ERASER : — I was going to say that both petrol 
and reinforced concrete are so much to the fore in 
these days that a little experiment in connection with 
the two might be quite interesting. 

In one or two of the tables there are blanks stand- 
ing in place of tests. Are we to assume that the cube 
or pat, whatever it might be, failed utterly at that 
point ? 

Mr. GADD : — Will you tell me what table that is ? 

MR. FRASER :— Well, Table C and Table E, 
Table C particularly. 

Mr. GADD :— May I explain that at once, Mr. 
President? If you notice, I say at the top of page 507 
that one specimen for each period was removed from 
the water after twenty -six days. Those blanks repre- 
sent the specimen removed, and they are tested later 
on, you notice, in Table D. 

Mr. FRASER : — Yes. And then Table E ; you 
have apparently no test for one month and three months 
in colza-oil in water and air, as no results are given. 

Mr. GADD : — The tests were made, but those are 
the results. The results were nil ; there was no 
strength. 

Mr. FRASER :— I see, they failed utterly. I 
should just like to add my thanks to those of Mr. Alban 
Scott and Mr. Butler. I think this is by far the best 
paper that has ever been read at the Institute. It is 
astounding the amount of information that is given ; in 
fact, its value is one of its faults, really, for this reason, 
that so much information is given, and so wisely, that 
I am afraid members will be acting upon it without 
asking the question as to how these tests were carried 
out, and, considering the Concrete Institute publish 
these, and in a way render them authentic, I think the 
author might give us some hint as to the actual testing 
of these cubes. He is a chemist, and we do not doubt 
for a moment his ability to carry out chemical tests, 
but I think, as to the actual crushing tests and tensile 



TWENTY-NINTH MEETING, Dec. 12, 1912 52 r 

tests it should be stated on what instrument these tests 
were done, and probably by whom. 

Mr. W. G. PERKINS, District Surveyor for 
Holborn (Member of Council ) : — I should just like 
to say a word. I will not be long. I think 
Mr. Gadd's paper is most opportune, because at 
the present time there are in the market a number 
of patent preparations or compositions which we are 
told to add to our cement to make it waterproof. Now, 
I believe some of those patent things are fatty acids ; 
at all events, I was told so in the case I had recently 
where I took legal proceedings against a builder for 
mixing a certain powder with his cement and using it 
for a damp-proof course. I served the builder with 
a notice, and he would not comply with it. The result 
was I took him to the police-court. During the course 
of the case they called an agent for the proprietors 
of this material, who went into the witness-box and 
said it was a fatty acid, the composition of which was 
a trade secret. That did not seem to satisfy the magis- 
trate, and as a result the builder was fined £5. I 
have since had that damp -course taken out. I do 
not know whether I was right or wrong in my action. 
If I always took up that attitude, I might be stopping 
the use of a valuable article. I should like to know 
from Mr. Gadd whether he thinks the addition of 
these materials — I need not mention them by name ; 
you can see them advertised in the pages of all the 
professional journals — is detrimental to cement and 
concrete. 

Mr. FREDERIC W. HINGSTON, M. Quantity Sur- 
veyors' Association, M.C.I. : — I should like to say I 
have recently had experience in taking out the quantities 
for a reinforced concrete bath which has been made 
watertight by being rendered on the inside with one of 
these patent materials with no other waterproofing 
material at all. I would be very much obliged if 
Mr. Gadd would tell us, if he can, whether that material 
has any effect on the concrete either one way or the 
other. It would be most interesting to me, and I am 
sure to other members of the Institute. 

Mr. G. C. WORKMAN, M.S.E. (Member of Coun- 
cil ) : — While we are on the same subject I would 
like to ask a question also. I was reading a few 



=>22 THE CONCRETE INSTITUTE 

days ago an article — an extract from an American 
paper— where experiments were given concerning the 
waterproofing of concrete by the addition of a small 
quantity of soap. The tests given were very remark- 
able. Mr. Gadd says in his paper that all the tests 
that he has made here bring out the destructive action 
of saponifiable vegetable oil. I want to ask if this 
means that there is some danger in mixing soap with 
the concrete, assuming that it has that beneficial effect 
of making it watertight ? 

Referring to the whole trend of this paper, I am 
very pleased to see that it absolutely confirms what 
I have always held to be a rule for concrete engineers 
to work upon when dealing with any of these oils or 
acids, namely, that it seems, by various tests which 
have been made, that mineral oils do not appear to 
affect the concrete, whereas animal and vegetable oils 
seem to affect it — that is, if the concrete is to resist 
the effects of cold mineral oils. From all the infor- 
mation I have been able to gather from tests and 
reports from various sources on the subject, all I 
have read seems to be borne out by Mr. Gadd's experi- 
ments, which are certainly of great value, and which 
I have no doubt will be very useful to reinforced con- 
crete engineers in particular, seeing that they often 
have to deal with the question of reservoirs and pipes 
which have to contain fats and acids. 

With regard to naphtha and various other mineral 
oils, I am inclined to think there is no danger in 
making reinforced concrete reservoirs and pipes to 
contain this mineral if cold. I have seen small 
reservoirs filled with crude mineral oil, and I have 
been told that the oil had been standing there for 
three months without any detrimental effect to the 
reservoirs. I have been told that at Baku and various 
other places large reservoirs are used for the storage 
of naphtha, and, as far as I can find out, they seem 
all right, but still, there seems to be a certain amount 
of doubt on the subject, and those who know some- 
thing about these things keep them secret. I should 
like Mr. Gadd's opinion as to those very important 
questions. 

Mr. VAWDREY :— Just one question, and that is, 
At what age is concrete sufficiently indurated to resist 



TWENTY-NINTH MEETING, Dec. 12, 1912 523 

the action of mineral oil ? It appears it does so after 
a certain age ; at what age does Mr. Gadd consider 
the dangerous period is past ? 

THE PRESIDENT :— With reference to the ques- 
tion of waterproofing compounds, I have found in all 
cases after three months the crushing strength is 
gradually reduced. I am making some further ex- 
periments with waterproofing compounds guaranteed 
to increase the strength. After about a couple of 
years I shall be able to give some information on the 
subject. 

I will now ask Mr. Gadd if he will reply briefly 
to the remarks made by the various speakers. If he 
wishes to elaborate later on by letter, we will be very 
pleased to have his communication. 

Mr. GADD :— Mr. President, I hope I shall be 
able to answer all the points raised by various speakers, 
but I am afraid, not being a shorthand writer, that the 
notes I have are rather scrappy, and I am not sure 
that I shall be able to make them all out. 

To commence with Mr. Butler, if I may. He asked 
what effect the immersion of cement in beer had upon 
the setting-time. I am sorry I 'cannot give that at the 
moment . I believe I made a note of it, but it is not 
now within my memory. Then. Mr. Butler raised a 
point which is quite justifiable, and which. I admit, 
detracts something from the. value of the results, 
although not very much. He drew attention to the 
facts that the results of crushing and tensile tests are 
the average of only two or three duplicate tests. I can 
only say that I should have preferred to make a larger 
number of tests, but the number is already fairly large, 
and there is a limit to one's available time and storage- 
room. As I remarked in introducing the paper, I do 
not profess it to be an exhaustive treatment of the sub- 
ject, but, at the same time, I think you may accept the 
results from even two or three tests as an indication 
of the truth. My object in bringing this before the 
Institute was rather to commence a line of investiga- 
tion, which, I hope, will be followed up not only by 
myself but by other members. 

Mr. Butler suggested that it would have been better 
to immerse water-gauged briquettes in tannic acid 
rather than gauge with the acid solution itself. I am 



524 THE CONCRETE INSTITUTE 

prepared to admit that in one sense this would be true, 
as it would approximate more nearly to actual condi- 
tions in practice, but in another sense this objection 
does not apply. The object was to ascertain the action 
of tannic acid on concrete, and gauging the cement 
with the solution brings the acid into more intimate 
contact with every portion of the mortar. 

Mr. Butler's point about greasing moulds is an excel- 
lent one. It did not occur to me to make it in the 
course of the paper, but you certainly do not grease 
a mould with the object of causing a briquette to stick 
to it. 

In answer to further questions, the oil or grease 
was mixed with the dry cement by rubbing in a 
mortar, the harder fats, like lard, being slightly warmed 
to enable this to be done. Afterwards the sand was 
added and the whole well mixed, and finally the mass 
was gauged with water. 

The form of percolator used is rather difficult to 
describe verbally, but it consists essentially of two 
cast-iron cups of square form, between which the 
concrete slab is squeezed by means of large screwed 
rods and nuts, indiarubber washers i in. thick forming 
watertight joints and cushions. The upper cup is 
provided with an inlet for water, and the lower cup 
has an exit, too, for the water, which is forced 
through the slab. Pressure is obtained by means of 
a pump, and an accumulator retains the pressure con- 
stant, indicated by a pressure-gauge. I shall be glad 
to give Mr. Butler a sketch afterwards. 

Mr. BUTLER :— Thank you. 

Mr. GADD : — I do not know whether I have 
answered all Mr. Butler's questions before I leave 
him. With regard to Table H, he remarked that it 
was rather curious that test -pieces immersed in cotton- 
seed oil showed a certain strength at one period and 
nothing at another. Well, I am afraid I cannot 
explain that except in one of two ways : either that 
some of the briquettes, although they were all made 
by the same gauger, were perhaps a little denser 
than others ; or, as there, are only two briquettes 
tested, the average is not good enough — there were 
not sufficient of them to get a fair result. 



TWENTY-NINTH MEETING, Dec. 12, 1912 525 

Mr. BUTLER :— Table G especially. 

Mr. GADD : — What about that? I see what you 
mean : that it dropped at six months. 

Mr. BUTLER :— No ; Table G— " Tensile strength 
nothing." 

Mr. GADD :— Well, absolutely nothing ; that is 
quite so. You see, there were only two briquettes 
tested at each period, but in neither case would they 
stand the weight of the clips — they had no resistance 
at all. 

Mr. BUTLER : — You had a crushing strength over 
1,000. 

Mr. GADD : — Yes ; it is very curious. I do not 
propose to-night to try to explain it. These are the 
results I got, and that is all I can say about them. 

Now I may leave Mr. Butler, and I hope if I have 
left anything unanswered he will let me know after- 
wards. Mr. Alban Scott made some remark about 
percolation through concrete, and he said he found 
in his experience that after a time even concrete which 
was porous closed up. Well, of course, that is the 
experience of everybody ; it does close up. As the 
concrete goes on hydrating, setting, and indurating 
the pores gradually close up, and, personally, I know 
no better way of making concrete waterproof than 
to force water through it for an hour or two under 
very high pressure. If you do that, and then let it 
dry, it is then almost " absolutely waterproof — that is, 
assuming it is concrete and not a sponge. 

Mr. Alban Scott also raised the question as to why 
two cubes only were tested. I have answered that ; 
I am sorry there were not more. 

Mr. Vawdrey asked me to what extent do I attribute 
a diminution in the size of the block. I am afraid 
I did not quite follow him there. I did not measure 
the blocks, but I did not observe that there was any 
diminution whatever. 

Mr. VAW r DREY : — In one case the block was 
actually reduced to mud. I wondered, in the other 
case, whether that action had been going on from the 
outside. 

MM 



526 THE COXCRETE INSTITUTE 

Mr. GADD : — Oh, yes ; that is quite right. The 
edges were worn ; there were no sharp edges. Even 
in those briquettes which stood a certain amount of 
strain the outside was rather indeterminate in shape. 

Mr. VAWDREY : — Then, to a certain extent, the 
sectional area had been reduced, I take it ? 

Mr. GADD : — Undoubtedly. You also asked me 
to explain the term ""saponification." Well, if you 
attempt to do so simply, it means the decomposition 
of a neutral oil. When I speak of a neutral oil I 
want it to be quite understood that the ordinary oils, 
as we know them, are not fatty acids ; they are com- 
pounds of the fatty acids, just in the same way as salt 
is a compound of hydrochloric acid. But the neutral 
oils are decomposed by calcium hydrate — we will say- 
split up — and in that process form a soap. As I 
have explained in the paper, tallow largely consists of 
tristearin ; it is a compound in which a portion of 
the hydrogen of the fatty acid is replaced by the 
glycerin radical C,H 5 , and the process of saponification 
is merely to dissociate the glycerin radica'l from the 
fatty acid. The glycerin is set free, or, rather, the 
glycerin radical combines with the elements of water, 
to form glycerin, as we know it ; the fatty acid which 
was formerly in combination with the glycerin radical 
goes into combination with the lime. The reason it 
is called saponification is because the metallic salts 
which are formed from these fatty acids are all soaps ; 
hence the term " saponification," or the production 
of a soap. That is not very clear, perhaps, to you? 

Mr. VAWDREY :— Yes, I follow it. 

Mr. GADD : — Well, it is not a subject which can 
be explained in two or three words. You also asked 
me, Mr. Vawdrey, in effect to reassure you as to my 
qualifications for carrying out the physical tests which 
I have given in the paper. 

Mr. VAWDREY :— Not I. 

Mr. GADD :— Well, somebody did it. I do not 
know who it was. One speaker was good enough 
to say no doubt I was capable of making chemical 
analyses, but he would like to know what my qualifica- 
tions were for making physical tests. If it is any 



TWENTY-NINTH MEETING, Dec. 12, 1912 527 

assurance to him I may say that I am making these 
physical tests every day of my life, that I am respon- 
sible for all the physical tests made at the Central 
Laboratory of the Associated Portland Cement Manu- 
facturers, and that these briquettes and cubes were 
gauged under my supervision by my regular staff, who 
are expert gaugers. 

Mr. FRASER : — I would like to apologize if 

Mr. GADD : — Not at all ; you were perfectly right 
to ask. 

MR. FRASER :— I thought that would be right to 
the general public who do not know your name as 
well as I do . 

Mr. GADD : — Do not apologize, you were quite 
right to ask. 

Another speaker, whose name unfortunately I have 
not got, had something to say about the various water- 
proofing compounds which are being pushed pretty 
well on the market just now. Well, I am not interested 
in waterproof compounds either one way or the other. 
I have no interest in praising them, I have no interest 
whatever in damning them, but I have, as a matter of 
fact, for my own information and the information 
of my directors, examined, analysed, and tested in 
relation to their effect upon tensile and crushing 
strength, and on waterproofing in particular, practic- 
ally all the water -proofing compounds there are on the 
market. I may go so far as to say that generally 
speaking they are all the same ; I cannot at the 
moment call to mind one which differs from all the 
rest. 

Mr. PERKINS :— May I interrupt, sir? One of 
them, for instance, is in the form of a paste, another 
is in the form of a powder. 

Mr. GADD : — Yes, but they all agree in principle ; 
they are all the same. 

Mr. PERKINS : — The same in chemical composi- 
tion ? 

Mr. GADD : — They are the same material ; one 
is mixed with water and the other is not, that is all. 



528 THE CONCRETE INSTITUTE 

MR. PERKINS : — The proprietor of one assures 
me it will not mix with water. 

Mr. GADD : — Quite so, neither will it in a way. 
It is a paste of a sort ; it is an emulsion really. But 
I may tell you the basis of practically all of them is 
the same. It is supposed to be this very lime soap 
or calcium stearate which I mention on page 508 of 
the paper. There are one or two exceptions, but as 
a matter of fact the bulk of them (I hope I am not 
giving away anybody who is present) — the bulk of 
these compounds consists of hydrate of lime with 
about 10 per cent, of lime soap. The reason of this 
is that although supposed to be calcium stearate, owing 
to the crude way in which the fat is saponified, they 
only get about 10 per cent, of calcium stearate, and 
the rest is simply lime and free fat, whether it is 
mixed with water, as our friend says, or whether it is 
dry. I quite agree that they may have some action 
in stopping up pores, so far as the free lime is con- 
cerned, that is to say, the lime hydrate, but I find 
myself that the calcium stearate part of it is a detriment 
rather than an assistance. I have not found a single 
one of these lime soap compounds which renders con- 
crete more waterproof than plain concrete, but rather 
the reverse. In my own tests the lime stearate, which 
is an insoluble and sticky sort of a material, has been 
absolutely detrimental so far as making concrete water- 
proof is concerned. 

Mr. HINGSTON : — May I ask you a question, sir, 
upon that ? 

Mr. GADD :— Yes. 

Mr. HINGSTON : — I ask you because, as I have said 
before, we have just done a reinforced concrete swim- 
ming-bath with this material, and I should like to 
know whether it has a detrimental effect upon the 
bath, and whether that effect is likely to be con- 
tinuous. In other words, will the bath be a failure 
in the course of a number of years ? 

Mr. GADD : — I do not think so. So far as my 
experience goes, I find that if you mix these water- 
proofing materials with concrete there is a loss of 
tensile and crushing strength which varies from 1 5 



TWENTY-NINTH MEETING, Dec. 12, 1912 529 

or 20 up to as much as 40 per cent, loss of strength, 
but the lime soap, which is the chemical basis of these 
things, is not a fatty acid ; it is a salt of a fatty acid 
and it has no effect itself upon the concrete. 

Mr. HINGSTON :— Thank you. 

Mr. GADD : — My objection to these waterproofing 
compounds is that they do not make concrete water- 
proof. I do not say that they damage the concrete. 

Mr. HINGSTON :— Well, in this particular case it is 
a swimming-bath, not a particularly large one, and the 
people guaranteed it to be waterproof. 

Mr. GADD : — Well, it may be, and I have seen 
such tanks and baths which are quite waterproof, but 
my contention is, if you had made the concrete properly 
without it it would be equally waterproof ; at any 
rate, that is what my own experiments lead me to. 

I think somebody else mentioned about waterproof- 
ing with soap. Well, in that case you have absolutely 
the same thing. If you gauge cement you liberate 
calcium hydrate ; in contact with soap there is an 
interchange of lime for soda ; the soda soap is decom- 
posed and this very calcium stearate or lime soap is 
formed. 

Mr. WORKMAN: — Does it weaken the concrete? 

Mr. GADD : — Well, it does, but I do not say 
seriously. In some of my experiments where 3, 4, 
or 5 per cent, of the material has been put in, it has 
weakened the concrete as much as 40 per cent., but 
that is the limit I have found. It certainly does not 
help the concrete. 

Mr. Workman also said he found that mineral oils 
do not affect concrete. I am quite with him there. 
I think it is perfectly safe to store mineral oil in a 
concrete tank, if it is entirely mineral oil . It certainly 
is not safe to store vegetable or animal oil in concrete 
tanks, but mineral oil, which is not saponifiable, I think 
it is perfectly justifiable to store in a well-made 
concrete tank. 

Mr. WORKMAN :— It will not affect them? 

Mr. GADD : — It will not affect the concrete 
chemically, although my experiments indicate some 



530 THE CONCRETE INSTITUTE 

loss of strength for physical reasons. The difficulty- 
is that in most cases you cannot make the concrete 
sufficiently tight ; light oils percolate through. 

Mr. WORKMAN :— That is the point. 

Mr. GADD : — They are not doing the concrete any 
harm chemically. 

Mr. WORKMAN :— I have been told this, that if 
these heavy oils are very much refined they become 
so light that they simply go through the concrete. 

Mr. GADD : — That is quite right. 

Mr. WORKMAN : — I have no evidence to show 
whether that is so or not. I am concerned with the 
storage of benzoline ; as a matter of fact, it is a very 
volatile oil. 

Mr. GADD : — Personally. I have not been able to 
make any concrete dense enough to prevent benzoline 
going through it. 

Mr. WORKMAN :— That is what I fear, too. 

Mr. GADD : — I think you will find the greatest 
difficulty to keep it in, but so far as acting on the 
concrete is concerned there is no danger whatever. 

The Meeting then terminated. 



THIRTIETH ORDINARY GENERAL MEETING 

Thursday, January 9, 191 3 

THE THIRTIETH ORDINARY GENERAL 
.MEETING of the CONCRETE INSTITUTE was 
held in the Lecture Hall at Denison House, 296, Vaux- 
hall Bridge Road, London, S.W., on Thursday, 
January 9, 1913, at 7.30 p.m., 

MR. E. P. WELLS, J. P. (the President), presiding. 

THE PRESIDENT : — The first business, gentlemen, 
for us this evening is to elect eleven members and 
two students, whose names I will put before you, and 
unless I hear to the contrary I will assume that they 
are elected. 

1. Mr. Perciyal M. COOPER, Chief Engineering 
Assistant with Messrs. Mais and Sant, A.M.M.I.C.E., 
Kingston, Jamaica. 

2. Mr. William Walker Dearle, M. Quan. Surv. 
Assoc, 13, John Street, Adelphi. 

3. Mr. J. Y. Haskell, Assistant Engineer in Rail- 
way Construction, P.W.D., Wellington, New Zealand. 

4. Mr. Frank Hill, Engineer -in-Chief's Office, 
General Post Office, 8, King Edward Street, E.C. 

5. Mr. Frederic William Hingston, M. Quan. 
Surv. Assoc, Portland House, Basinghall Street, E.C. 

6. Mr. Andrew Little, Engineer with Ocean Iron 
Works, Manchester. 

7. Mr. William Alexander Mackay, Structural 
Engineer, 94, Larkhall Rise, Clapham. 

8. Mr. Charles Newson, M.S.A., 92, Tooley 
Street, London Bridge, S.E. 

9. Mr. P. Y. Manickam Naicker, B.E., Execu- 
tive Engineer, P.W.D., Madras. 



532 THE CONCRETE INSTITUTE 

10. Mr. R. VlTTAL Rau, Supervisor, c o the Special 
Engineer. Hyderabad. Deccan, India. 

ii. Captain Arthur Johnson Savage, R.E.. 
First Assistant Superintendent, Building Works De- 
partment, No. 4, Staff Quarters, Royal Arsenal, 
Woolwich. 

1. Mr. Archibald John Buchanan Atkinson, 
Stud. Inst. C.E., Assistant Civil Engineeer, North 
Staffordshire Railway Company, Engineer's Office, 
Stoke-on-Trent. 

2. Mr. John P. Harvey, Draughtsman with Mr. 
Alexander Drew, M.I.Mech.E., 64, Victoria Street, 
S.W. 

This brings the total number of members up to date 
to 955. 

I will now call upon Mr. \ alentine Ball to read his 
paper on " Concrete in its Legal Aspect." 

Mr. W. VALENTINE BALL, Barrister-at-Law. then 
read his paper. 



CONCRETE IN ITS LEGAL ASPECT 

Preliminary. 

In presenting this paper one is beset with certain 
difficulties. There is no statute law which is specially 
applicable to the subject in hand, and of reported cases 
relating specially to concrete there are none. Never- 
theless, it has occurred to me that there are certain 
aspects of the law relating to building and engineering 
contracts which may be of interest to members of this 
Institute, and I am indebted to your Council for giving 
me this opportunity of setting them before you. I 
hope to draw attention to a few considerations which 
may properly be kept in view by the parties to a 
contract which involves the use of concrete or rein- 
forced concrete. 

I was prompted to prepare this paper by the fact 
that I recently came across a contract for the erection 
of large works which involved the use of 30,000 tons 
of cement ! It therefore occurred to me that the 
clauses as to concrete and reinforced concrete which 



THIRTIETH MEETING, January 9, 1913 533 

appear in engineering and building contracts are by 
no means a negligible part of these documents . 

In the course of the paper I propose to use the 
term " employer " to mean the local authority, com- 
pany, or person who requires the work to be carried 
out. The term " contractor " will signify the firm 
of contractors or builders employed directly by the 
employer, while the term " sub -contractor " will 
include any firm or company which is employed to 
carry out some portion of the work under a sub- 
contract. 

General Observations on the Employment of 

a Sub -CONTRACTOR. 

Your Secretary has been good enough to point out 
to me that the relations between contractor and sub- 
contractor are likely to be of special interest to 
members of the Institute. 

In carrying out a large contract the employment 
of sub -contractors or specialists is very common ; 
indeed, the employment of sub -contractors is almost 
inevitable when the work in hand is of any magnitude. 
Whether the work of making ordinary concrete is 
usually entrusted to a sub -contractor I do not know. 
But I presume that reinforced concrete will frequently 
be carried out under a sub -contract. The sub -con- 
tractor will be chosen by the engineer or architect 
acting in the interests of the employer. 

Generally speaking, where there is no stipulation 
against sub -contracting a contractor may employ sub- 
contractors. The rule is, however, subject to the 
qualification that it does not apply when the employer 
reasonably and naturally looks for the personal service 
and attention of the contractor. Thus, if the work in 
hand were of a highly special character, it would not 
be competent for the contractor who was skilled in 
that class of work to hand over its performance to 
some one else. It is otherwise, however, when the 
work involves the exercise of no special degree of 
skill. Cockburn, C. J., in British Waggon Co. v. Lea. 
1880, 5 Q.B.D. 149 (at p. 153), thus stated his views 
of the law on the subjeci : — 

" Much work is contracted for which it is known 



534 THE CONCRETE INSTITUTE 

can only be executed by means of sub -contracts ; 
much is contracted for as to which it is indifferent to 
the party for whom it is to be done whether it is done 
by the immediate party to the contract or by some one 
on his behalf. In all cases the maxim Qui facit per 
alium facit per se applies. - ' For instance, if I were 
to employ Messrs. A B to make a reinforced concrete 
bridge, that firm being particularly skilled in the work, 
they could not let the work out to Messrs. C D. 

Although there does not appear to be any English 
case on the point, it appears that neither an architect 
nor an engineer has implied authority to employ sub- 
contractors to do any part of the contract work, or 
any work which is extra to that work . The law has 
been so laid down in Canada (see Cowan v . Goderich 
Northern Gravel Co., 1859, 10 Up. Can. C.P. 87, 
cited in Hudson's " Building Contracts," vol. i., 
p. 161. In that case the plaintiff was a sub-contractor 
employed by head contractors who were constructing a 
road for the defendants. The defendant's engineer 
instructed the plaintiffs to do certain work for the 
price of which the action was brought. It was held 
that the action did not lie, as the engineer had no 
authority to give the order in question. The following 
clause may be inserted if it is desired to ensure that 
the contractor shall carry out all the work himself : — 

" This contract is and shall be considered as 
a personal contract by the contractor himself, 
who shall personally, with the assistance of skilled 
foremen, agents, mechanics, and workmen, direct 
and execute the works." 



The more approved practice, however, is to leave 
it to the engineer to say whether and how far sub- 
contractors may be employed. The following clause, 
which is to be found in the model conditions approved 
by the Institute of Electrical Engineers, may safely 
be used : — 

' The contractor shall not, without the consent 
in writing of the engineer, assign his contract, 
or any substantial part thereof, nor under -let the 



THIRTIETH MEETING, January 9, 1913 535 

same, or any substantial part thereof, nor make 
any sub -contract with any person or persons for 
the execution of any portion of the works, other 
than for raw materials, for minor details, or for 
any part of the whole of which the makers are 
named in the contract." 

Another form of clause prevents the contractor from 
making a sub -contract with any workman or workmen 
for the execution of any portion of the work, except 
with the consent of the engineer. It also provides that 
if the contractor shall sub-let or let at task work any 
portion of the work he shall in such case forfeit to 
the employer the sum of £100 as liquidated damages. 

Who is Liable to Pay the Sub -Contractor? 

A most important question from the point of view 
of the sub -contractor is, Who is liable to pay him? 
He naturally wants to be sure that his labour will not 
be in vain. Generally speaking, the employer is not 
liable to a sub-contractor, unless an agreement between 
them can be proved. Such an agreement will not be 
implied from the mere acceptance of the sub- 
contractor's work. Thus, if A were to ask you to 
lay the concrete foundations for B's house, and you 
did the work, the mere fact that B accepted it and 
thanked you very much, would not make him liable 
to pay for it. For instance, where an employer con- 
tracted with a builder to do certain work on his house, 
and a tradesman supplied goods to the builder for use 
on the house, it was held that the employer was not 
liable for their price (see the case of Brahmah v. 
Abingdon, cited in Pater son v. Gandasequi, 18 12, 
15 East. 62). The employer does, however, become 
liable if it can be shown that there is a contract 
between him and the sub -contractor. For instance, 
in another case a contractor employed a mason to do 
certain work as extra to the contract. In an action 
for work and materials by the mason against the con- 
tractor's employer the plaintiff stated that the work 
in question was extra to the contractor's contract, and 
that he had agreed with the contractor to do the work. 
On production of the contractor's contract the jury 



536 THE CONCRETE INSTITUTE 

found that there was a distinct contract between the 
mason and the employer for the work sued on, and 
judgment was entered for the plaintiff (Eccles v. 
Southern, 1861, 3 F. and F. 142). 

An employer may also become liable to a sub- 
contractor by going surety for him. In that case, 
however, there must be something in writing, as a 
contract of guaranty cannot be sued on unless it is 
in writing. But there is a difference between a promise 
to pay the debt of another and a direct promise to be 
liable oneself in any event. In the latter case a written 
contract need not be proved. Thus, if the employer 
promises to pay the sub -contractor out of monies which 
he has to pay to the head contractor, this would be 
treated as a direct promise 10 pay {Dixon v. Hatfield, 
1825, 2 Bing. 439). 

There is another way in which the employer may 
become directly liable to a sub -contractor. It may 
be proved that the head contractor, in employing the 
sub -contractor, really acted as the agent for the 
employer. The onus of proving this will be on the 
sub -contractor (see Woodward v. Buchanan, 1870, 
L.R. 5 Q.B. 285). 

The question, Who is the sub -contractor to look to 
for his remuneration ? therefore turns upon the con- 
ditions of his employment. In the ordinary form of 
agreement a clause is inserted providing that the con- 
tractor will pay to the sub -contractor " the sum of 
£ when the engineer for the time being of the 
employer shall have certified in writing that the said 
work has been completed and finished to his satisfac- 
tion." Other terms are sometimes inserted providing 
for payment by instalments. 

The question of liability largely depends upon 
whether the contractor was constituted the agent of 
the employer to employ the sub -contractor or to pur- 
chase goods from him, and to establish privity of 
contract between the employer and such sub -contractor. 
Where the defendant (a building-owner) entered into 
a contract with a builder by which the latter agreed 
to build a house for him under the supervision of an 
architect, the contract provided that the provisional 
sums for goods to be ordered from special artists or 
tradesmen should, as the architect should certify, be 



THIRTIETH MEETING, January 9, 1913 537 

payable by the builder or the building-owner. The 
exact terms of the clause were that : — 

" The provisional sums mentioned in the speci- 
fication for materials to be supplied or for work 
to be performed by special artists or tradesmen, 
or for other works or fittings to the building, 
shall be paid and expended at such time and in 
such amounts and to and in favour of such persons 
as the architect shall direct, and sums so expended 
shall be payable by the contractor without dis- 
count or deduction or by the employer to the 
said artists or tradesmen." 

Special goods according to a particular design were 
ordered by the builder from the plaintiff, who was 
a metal-worker, and the architect certified the sums 
for these goods as due from the defendant to the 
plaintiff, deducting the amount from the certificate given 
to the builder. It was held that the plaintiff was 
entitled to recover this sum direct from the building- 
owner (Hobbs v. Turner, 1901, 18 T.L.R. 235, 
which was followed by Mr. Justice Channell in the 
recent case of Cattail v. The London County Council 
(191 o), 75 J. P. 203). In the absence of such a 
clause, a specialist or sub -contractor would be com- 
pelled to look for his remuneration to the person who 
directly employed him— namely, the head contractor. 

Where the Contractor becomes Insolvent. 

Trouble frequently arises in cases where, owing to 
the insolvency of the builder, the sub -contractor is 
compelled to look to the building-owner. He often 
makes such a claim without avail ; but by means of 
a special clause this difficulty may be obviated. So 
In re Wilkinson ex parte Fowler (1905, 2 K.B. 713), 
a District Council entered into a contract with a con- 
tractor for the construction of certain sewerage works. 
The contract provided that certain machinery for the 
works was to be supplied to the contractor by certain 
specified firms, and that " if the engineer shall have 
reasonable cause to believe that the contractor is unduly 
delaying proper payment to the firms supplying the 



538 THE CONCRETE INSTITUTE 

machinery, he shall have power, if he thinks fit, to 
order direct payment to them." The contractor having 
become bankrupt, it was held that the engineer had 
power to direct the payments to be made to the 
machinery firms direct. Mr. Justice Bigham said : 
" I think that the clauss means that if the persons 
supplying machinery to the contractor for the purpose 
of the contract are not promptly and properly paid 
by him they can apply to the engineer, and then it 
shall be competent for the engineer to intervene, and 
by a proper certificate given in that behalf to require 
the council to pay to the machinery firms the amount 
of their accounts directly — that is to say, not through 
the hands of the contractor at all, but the money is 
to be paid directly by the council to the machinery 
firms." 

how far the contractor is liable for the 
Delay of the Sub-Contractor. 

Assuming there is delay in the execution of the 
work, the question of liability may arise as between 
the contractor and the sub -contractor. One may blame 
the other, and the employer may leave them to fight 
it out between themselves. 

If an employer reserves to himself the right of 
employing specialists to do any portion of the work 
on a large contract, he does not thereby give any 
implied undertaking to the head contractor that he 
will be responsible for any damage caused to the 
builder by any delay or default on the part of the 
specialists. In the case of Mitchell v. Guildford Union 
(1903, 68 J. P. 54) a builder undertook to do the 
whole of a certain piece of work for a certain sum, 
but part of it was to be done by specialists. The 
builder undertook to finish the work by a certain 
date unless he was hindered by {inter alia ) delay on 
the part of the engineer or specialists. The builder 
was not to be liable for any defects in work provided 
by the specialists, unless by the reason of contributory 
negligence on his part, or his having paid any final 
balance to the specialists without first having the archi- 
tects' written authority to do so. In the course of 
the work there was delay on the part of the specialists, 



THIRTIETH MEETING, January 9, 1913 539 

whereby the builder suffered damage. The builder 
brought an action for breach of contract against the 
building-owners, alleging that under the contract and 
specification there was an implied promise on the part 
of the building-owners that the delivering and pricing 
should be done at such reasonable times as to enable 
the builder to complete his work within a reasonable 
time thereafter, and that the building-owners had 
broken one or both of these implied promises. It 
was held that on the proper construction of the con- 
tract and specification there was no such implied 
promise, and that there was no breach of contract on 
the part of the building-owners affording the builder 
a right to damages. (See also Leslie v. Metropolitan 
Asylums District, 1901, 68 J. P. 86.) As a general 
rule, however, the sub -contract contains a clause to 
the effect that " the sub -contractor shall pay to the 
contractor the sum of £ as liquidated damages, and 
not by way of penalty per day for each day after the 
day of that the work shall not be finished or 

complete, and it shall be lawful for the said contractor 
to retain the said sums out of any money payable t